"Chest-nuts burst-ing, all over the ovennnn..."

'Twas the night before Bake Off, when all through the house,

one baker was stirring, cocoa all over her blouse.

The parchment was lined in the cake pan with care,

in hopes that the batter would soon be in there.

When out of the oven sounded such a loud bang,

that the bowl nearly fell to the floor with a clang!

Away to the oven I flew like a flash,

threw open the door and had all my hopes dashed.

A great wave of heat rushed up into my eyes,

yet not from that sprung the tears, but from the surprise.

The walls of the oven showed I was a clutz:

splattered bits everywhere, in place of chestnuts.

I apologize, I don't know what happened there.  I need to get out more.  As is probably now clear, despite hearing Nat King Cole croon about chestnuts annually, I had next to zero familiarity with the shiny brown nuts prior to my blowing them up.  What possessed me, then, to want to bake a chestnut coffee cake, I do not know.  It was, in fact, the night of the Bake Off finale in early October, but I was already feeling a touch of holiday spirit.  So when I saw Bon Appétite's recipe for Chestnut Coffee Cake earlier on in the day, it grabbed my attention.  Never mind that I didn't know how to handle chestnuts, it couldn't be that hard, right?

I bought some lovely-looking nuts from the local market and took them home to get started.  The recipe calls for nuts in a vacuum-pack or a jar, but while I'd seen some in a can in the grocery store I hadn't seen any others.  Since fresh ones were available I thought they'd be best, plus I wanted to try roasting them first (not called for in the recipe) and wasn't sure about trying to roast chestnuts which had already been peeled, such as those in the can.  What I didn't think about was the possibility of rotten nuts.  Or blowing them up.

Of course, I knew the scoring of the nuts, as directed by BBC Food, was to allow for expansion; I expected the skins to open up, but for some reason it never occurred to me that they might start popping like popcorn.  So I scored them and put them in the oven to roast, uncovered.  The bang like the shot of a gun in the corner of the kitchen caught me totally off guard, and the mess inside... it wasn't pretty.  Only one nut had burst, but it had done so with gusto, coating the entire inside of the oven - top, bottom and sides - with a soft powder of chestnut guts.

I pulled the hot roasting pan from the oven and let the nuts cool while I aired out and cleaned out the oven.  By the time that was finished and I was no longer worried about any of the remaining chestnuts exploding in my face, I investigated them.  Some seemed ready to be peeled, but a number of them were discoloured inside.  I'd happened upon advice in another recipe to over-buy chestnuts because they often have rotten centres.  Without knowing what exactly a rotten centre looked like, or how to tell if my chestnuts were bad, I ran out and bought the canned variety.  It's never worth risking making people sick, and this cake wasn't just for me.

The canned variety come suspended in some sort of thick liquid, so I rinsed them off and then stuck them in to roast very very briefly before chopping them up.  The chopped nuts are then (or first, if you skip the roasting) cooked in a skillet with water and brown sugar to make a syrup.  The recipe calls for a half-cup of chestnuts, but I believe I might actually have gone a little crazy with the chestnut chopping (revenge therapy for the chestnut exploding?) and ended up using a full cup; if so I would also have doubled the water and sugar, as well as the cocoa and remaining sugar for coating.

There were a lot of nuts.  I let those cool while making the streusel topping.  This, unlike the nut fiasco, was very straightforward: simply mix almond meal, sugar, flour and salt and work the chunks of butter into it with your hands.  The cake recipe itself is very easy and fairly standard, with the inclusion of sour cream.  After the batter was made, I worked pretty quickly to get half of it in the pan and then to crumble a layer of the cocoa-coated chestnuts over it before topping it off with the second half of the batter and finally the streusel.

The recipe says to sprinkle the chestnuts over the first layer of batter, but mine were pretty sticky and thick, and not really sprinkle material...  I also had twice the amount, so rather than a chestnut here and a chestnut there, I wound up with an entire layer's worth.  In the end I quite liked it that way.

Unfortunately, even after my fallen cake and my flooded cake, I was still adjusting to my new oven (I still am, in fact), and one side got a little to near to the flame in the back.  Open fires, huh?  So it was singed and certainly wouldn't have won me any star baker accolades, but it was far from inedible.  Having had, as I mentioned, no previous experience with chestnuts I was surprised to find that they were meaty, but they really do work with the chocolate and the somewhat crumbly spongy texture of the coffee cake.  It was good for enjoying with friends (and their goodies!) during the finale of Bake Off, and a leftover slice was equally tasty with coffee the next morning.

... And Then the Flood

Continuing in the spirit of Great British Bake Off-inspired experimentation, I moved from a cake without any chemical leavening agents to a cake without any chemical leavening agents and without any flour.  No flour!  That's right all you gluten-free people out there.  It is not that there is a flour-substitute in this cake - there isn't.  It is made only with chocolate, sugar, water, butter, eggs and coffee.  Some flourless chocolate cakes use similar ingredients but are treated almost as souffles, with soft peak egg whites folded into the batter to raise the cake.  This results in a 'fallen' look to the top of the cake when it cools.  This cake, however, is not really leavened at all.  Something akin to a mousse is made through combining melted chocolate, butter and sugar with beaten whole eggs and coffee.  It is not folded into anything, however, and no heavy cream or gelatin is involved.  The batter is simply poured into the prepared pan and baked in a bain-marie.

I say 'simply', and it generally is, but please take more care than I did - there will be less stress in the end.  In order to easily remove the cake after baking, I used a springform pan.  I used two springform pans actually: a 9" for the cake and an 11" for the bain-marie.  I took care to line the inside of the larger pan with foil so that the water would not leak out of it.  I did not, however, line the outside of the smaller pan to keep the water from leaking in...

Fold pieces of foil several times in the centre to waterproof.

I chose this recipe from Nick Malgieri, or rather was given it by my sister, because it was the nearest version either of us knew to the flourless chocolate cake that we used to decorate in the bakery.  I adapted it to fill a 9" pan instead of an 8", and this version can be found in the Recipe Box, along with the salted caramel and whisky sauce (see below).

If the chocolate does not melt, reheat gently over a double boiler.

While I'd seen the cakes baked many times, and eaten them many times, I'd never actually made any myself; hence the experimentation.  I did remember that the bakery used esspresso in the cakes, so I got a double shot and mixed that with enough pour-over coffee to make a 1/4 cup.  I did not, however, remember the more important piece of information...

Let the coffee cool before whipping it into the eggs.

As I was lowering the cake into the bain-marie, and giving it a bit of a push into the water (I didn't think it should float - another genius move) I had visions of peeling foil off of the bottoms of the flourless chocolate cakes in the bakery.  'That's odd...', I started to think in the split second before the water began to gurgle up with increasing speed between the edge of the batter and the inside of the pan, before another leak sprung and then another.  The top of the cake had flooded before I could finish cursing.

Temper the eggs with a little bit of chocolate before combining.

I poured the water out and off of the cake as best as I could, and proceeded to put it in the oven with fingers crossed.  The oven was having heating issues as well, of course, requiring to be set at Gas Mark 5 despite the desired temperature being a mere 300F (150C); fortunately I had purchased a thermometer that morning.¹

Whip it all together...

When the timer went off, I held my breath, opened the oven and pulled out a cake submerged under a small lake.  More cursing.  I very nearly had my own personal bingate!  Instead, when trying to tip the cake over the sink (not into the rubbish) I noticed that it was holding together, so I changed tack and soaked up the water with paper towels, covered the top where it was dark and would have been at risk of burning, and put it back in the oven.  However long it was in there in the end, I couldn't say, but I removed it for good when I thought that it seemed set and the top a bit dry.

Not too bad, in spite of the flood.

While the cake was cooling, I set to making salted caramel and whisky sauce to cover up any less aesthetically-pleasing aspects of the cake.  Salted caramel whisky sauce also has the added benefit, of course, of being utterly and totally delicious.  But you can leave it off if you like, your call.

I made this caramel once before, but in its original calvados incarnation in a recipe from BBC Food.  This time I substituted whisky and added about a 1/4 tsp of coarse Breton sea salt (for a very Celtic sauce, I suppose).  I thought that the sauce might have needed a bit of reheating before serving, but it was fine at room temperature.  If left in the refrigerator overnight, however, prepare for it to be spreadable.

Not bad for gluten-free.

¹ It really make me wonder what I baked the last three cakes at, though...

First Came the Fall...

The colours of the leaves are changing and there is a chill in the air.  The arrival of the Pumpkin Spice latte has been declaimed from every window of every Starbucks on every corner.  It's Autumn!  And though the Fall inspired this cake, unfortunately it wasn't the only kind involved in its making.

I've been watching too much Great British Bake Off (again) and as a direct result decided that I should challenge myself to make something other than my standard butter cakes for a layer cake that I was preparing for some friends' party.  I wanted to try a génoise cake, which is leavened with beaten eggs instead of baking powder and baking soda.  I also had a can of pumpkin lying around, and with the aforementioned arrival of Fall, I wanted to use it.  Happily, Williams-Sonoma had already beaten me to this combination, so I followed their recipes for both génoise cake and pumpkin mousse.  These are condensed in the Recipe Box.

I had to bake this cake twice.  The first time, the layer was pretty pancake-like; far too thin to be split.  The second attempt was far more successful.  The differences amount, I think, to the use of fresh eggs, the temperature at which the eggs are used, the degree to which they are beaten and the size of the tool used to fold the mixture.

Even though génoise is leavened with eggs, and the best eggs for whipping are fresh, I first unwisely elected to use some eggs that were perfectly safe but which had admittedly been in the fridge for awhile.  I also used them cold, straight out of that fridge, which may or may not have contributed to the failure of this layer.  For the génoise, the eggs are beaten whole with the sugar over a double boiler until they reach 140F (60C), or, for those of us without a candy thermometer, until the sugar is entirely dissolved.  They are then beaten on high until 'pale and tripled in volume'.  'Pale' may not be the best measurement, as I don't think the eggs had been whipped up enough to support the cake when I stopped at 'pale' the first time.  A better measurement is to stop when they hold a ribbon, which I later discovered Martha gives as one of her tips for this type of cake.

That is how far I beat the eggs the second time.  These eggs were also fresher and at room temperature when I used them.  Room temperature eggs create more volume, and therefore are likely to produce a better result in a cake in which they are the leavening agent.  The final important difference between the first cake and the second was the size of the folding tool.  The dry ingredients must be carefully folded into the beaten egg and sugar mix, and the wider the spatula the more effective each fold.  None of my spatulas are particularly wide, and with the first cake I could hear the bubbles in the batter popping with every turn of the bowl and twist of the spatula.  To try to minimize this damage, I used a cake scraper the second time.  While this was a bit messier because the scraper lacks a handle, it did work quite well.

The same recipe, same ingredients and same amounts produced twice the cake.  What a difference a little practice makes!  The third or fourth time might really have been the charm, but with enough cake for three layers I quit while I was ahead.

The pumpkin mousse was far less problematic, once I got past the complications of using leaf gelatine instead of powdered.  The recipe calls for 2 1/4 tsp or one sachet of powdered gelatine, which through using Nigella's conversion and some maths (which of course I did not write down) I calculated equals 3 1/3 leaves of Dr Oetker's platinum grade leaf gelatine.  I don't know if that's actually accurate, but that's how much I used and it worked just fine.

First set the gelatine to soak as directed on the packet, and then mix a 1/2 cup of the pumpkin puree with the sugar and salt in a saucepan over medium heat until the sugar dissolves.  Mix in the gelatine and let it cool to room temperature before mixing it into the remaining pumpkin and adding the spices.  I didn't have any rum, so I substituted a 1/2 tblsp molasses mixed with a 1/2 tblsp calvados in the hopes that this would approximate its sweet dark flavour.

Like the dry ingredients of the génoise getting folded into the beaten eggs, the pumpkin mixture gets folded into whipped cream.  Whip the cream to soft peaks in a large bowl, and use a large spatula (or a cake scraper) to fold the pumpkin mixture into it in thirds.

To set up the cake, the layers should be built up inside of the clean springform pan.  I used the first, denser cake layer as the base layer of the cake, and split the second layer to make a three-layer cake; the recipe was intended to be two layers, but why have less cake when you can have more?  For a little added punch and moisture, I drizzled the residue of the rum-substitute onto the middle layer.

The whole thing should then be left in the refrigerator for at least four hours, but as I was using the cake the next day, and wanted it to be very stable on its journey, I froze it.  To finish it off, pipe a whipped cream border before serving.

The pumpkin mousse essentially tasted like a light pumpkin pie - not a bad thing in my book.  It was very good paired with the lightness of the génoise, and added a bit of moisture.  The crowning achievement of the cake, however, or its most resounding endorsement, was one host's claim that there had never been so much success in getting Brits to eat pumpkin.  Still, I doubt they'll be queuing up at Starbucks for a Pumpkin Spice latte any time soon.

Acid Cocoa

Self-rising flour can be a useful thing.  It saves on cabinet space and requires one less step in measuring.  I was really pleased with the result it produced in a Lemon Yogurt Cake, but I should have known something was amiss when a search for chocolate cake recipes using only self-rising flour and no other leavening agent produced very few results.

There's nothing inherently wrong with using self-rising flour in a chocolate cake, but when I tried one of the few recipes that met my 'self-rising flour only' requirement, this one from King Arthur Flour, I found it to be a bit dense, quite crumbly and a little dry.  There was a bit of an incident that could have been the root of the dryness... the oven got switched off (ah!).  I was standing right there to turn it back on, but as I found that I had to bake the cake much longer than I should have, it is possible that it lost more heat than I had realized.  It was not until later, however, that I noticed a review of the recipe mentioning the difficulty of cutting the cake without ripping it apart, and this leads me to suspect that the crumbling was not the fault of the oven.

I don't know what the source of the crumbling was, but I'm somewhat inclined to think that it might have been related to the use of self-rising flour with no added baking soda or baking powder.  Cocoa, it turns out, is acidic.  Who knew?  (Ok, many people I'm sure.  Joy the Baker did.  And now I do - and you!)  Both baking soda and baking powder, a derivative of baking soda, react chemically when mixed with an acid, and one by-product of this reaction is carbon monoxide that is released when exposed to the heat of the oven; it is this chemical reaction that serves to leaven the cake.  Another by-product of the reaction is the neutralization of the acid.  This, it seems to me (bearing in mind that I could be considered a chemist by no stretch of the imagination), is why many cake recipes call for both baking soda and baking powder.  As Craftsy explains it, this is 'a system of checks and balances. If a recipe contains baking soda to neutralize the acid in a recipe, it might not be enough leavening to give a decent lift to the baked good, but adding more baking soda might be too much in relation to the acid. Here’s where the baking powder comes in, to save the day by giving the recipe a little extra lift while maintaining a pleasant flavor.'  What they don't mention, however, is that the high pH of baking soda also enhances the Maillard reaction responsible for browning.  Huffington Post writer Amanda Greene explains the chemistry in some more detail and reports that cookies baked with baking powder substituted for baking soda, that is, cookies which did not have the Maillard reaction-enhancing high pH, tasted of their raw ingredients.

Because cocoa is an acid with a low pH, and there was no extra baking soda to neutralize it, it is possible that the Maillard reaction was affected.  I am not sure (again, barely an armchair chemist here) how this could have impacted the texture of the cake and caused it to become crumbly, but I certainly am curious!  Similarly, though the cake did rise without any additional leavener I wonder if that extra boost would have produced a fluffier result.

It's too bad experimenting with chocolate cake is so hard.  Better get back to the mixing bowl.

Merlyn (with a 'y')

"When he had listened to all this, Merlin went up to the King and asked: 'Why have my mother and I been brought into your presence?' 'My magicians have advised me,' answered Vortigern, 'that I should look for a fatherless man, so that my building can be sprinkled with his blood and thus stand firm.'  'Tell your magicians,' answered Merlin, 'that they'd be better served pouring me into a cake.'"¹

It's true: sprinkling the fatherless Merlin's blood over the building would not have steadied its foundation one bit, because the real problem was caused by a pair of dragons fighting beneath an underground pool.  Which is to say: it's not true at all.  Clearly.  That last bit about the cake, however, is especially untrue in that I made it up rather than Geoffrey of Monmouth or Nennius (with whom this episode - minus the cake -  first originated).  Nevertheless, pouring Merlyn (with a 'y') in a cake is tasty tasty tasty.  It's not the stuff of prophecy, but maybe it should be.

Merlyn (with a 'y') is a cream liqueur made by the Welsh distillery Penderyn.  It is delightful straight, but because I'm a fan of putting booze in cake, I couldn't resist...  The liqueur is made with cream, so it took no stretch of the imagination to think that it might taste nice in a whipped cream.  And because I love whiskey and chocolate, I decided to make a chocolate cake.  It also didn't hurt that I already had cocoa powder, and since I was operating in an ill-equipped dormitory kitchen, primarily with leftover ingredients, catering to what I could do (whip cream) and could use (chocolate) was key.  I used the chocolate cake recipe in the Recipe Box, but substituted self-rising flour for plain flour + baking powder.  I did get a bit extravagant, though, buying an entire container of baking soda for this one cake.  After the success of the self-rising flour in my yogurt cake, I had thought that I could get away with omitting baking soda from a chocolate cake.  I tried it that same week, and I was wrong.  More on that another time, perhaps...

Because I was using a tall, 6" cake tin, I halved the original recipe.  I was also short on liquid measuring tools (I had none), and so had to estimate measurements for the oil, buttermilk, coffee and Merlyn.  Because Merlyn wasn't in the original recipe, I allowed for it by dividing the amount of coffee and devoting half of it to the booze.

Guesstimation is an art, not a science...

The student kitchen was also lacking a mixer of any description, but thankfully one of my flatmates had brought one along from home.  It was a manual hand mixer, and this was the first time I'd ever used one to make a cake.  Surely, in the days before electricity, they were very effective; but that didn't stop me from being slightly afraid of a shaky foundation from a loose whipped cream.  So I sprinkled some Merlyn over it... just kidding.  Instead, I purchased extra thick heavy cream, thinking that it would make for a naturally firm whipped cream.  When I opened the lid of the stuff, it was so thick that I was worried it wouldn't whip at all!  I could have turned the container upside down and it would have hung in there like an aging rock star clinging to his youth.  In the end all my fears were unfounded: after a small learning curve, the manual mixer did the job very well, and the whipped cream was thick and fluffy and the leftovers (I know, leftovers! Don't worry, they were eaten...) never deflated.

I used the manual mixer on the cake batter too, and despite the lack of measuring tools and the use of a possibly-questionable oven, it baked well.

To finish the cake, I wanted to cover it in ganache.  The recipe for ganache is also in the Recipe Box.  Normally I just use a store-brand bar (or several) of dark chocolate, but the local store didn't have any, so I went for a pair of large Cadbury Bournville chocolate bars.  Candy bar chocolate can sometimes have a waxy texture that isn't that desirable to begin with, but which also doesn't translate well into ganache - it can go grainy or be temperamental when melting.  I'm no doctor of chocolate, but I suspect that's something to do with some additive designed to stop candy bar chocolate from melting.

The Bournville chocolate, however, works well.  It is a bit softer than darker chocolate, so I added more of it to the cream than I might have otherwise - about a bar and a half total.

Chocolate ribbons just starting to form.

While the ganache was setting, I got going on setting up the rest of the cake: splitting the layers, whipping the cream... that's it really; this was a gloriously simple cake!

After the ganache had set, I spread some on the bottom layer of cake to test my suspicions that it wouldn't be thick enough to pour over the whole thing.  It was not liquid by any means, but it was at this point that I decided to add the extra half-bar of chocolate.  If the ganache has already cooled when you decide to add more chocolate, melt the chocolate on its own and stir it into the prepared ganache.  If the ganache has been stored in the refrigerator, let it reach room temperature or warm it up in the microwave before adding the melted chocolate to prevent it from freezing up.

Merlyn cake: surely the recipe was in the Liber Vetusissimus or somewhere.  Geoffrey probably just didn't have a sweet tooth.

¹Thorpe, trans., Geoffrey of Monmouth: The History of the Kings of Britain, p. 168, except for the bit about the cake.  There's some weird stuff in Geoffrey, especially in and around the Merlin material, but cake is not one of those things.

Pop-up Ty 2: Teisen mewn Tafarn

Not far from where the girls of Llanbadarn once rebuffed the poet Dafydd ap Gwilym, I carried a birthday cake into a pub and hoped not to cause my own trafferth or 'commotion' - one of the fire alarm/indoor sprinklers variety.

You see, the cake was a birthday cake, and you can't have a birthday cake without candles.  Unfortunately where there are candles there is fire, and when that fire is inside a building it is often followed by an unsolicited cold shower.  Perhaps not if the birthday boy or girl requires only one or two or three candles, but this one required considerably more... which is, after all, why the celebration took place in a pub in the first place.

In this edition of Pop-up Tŷ, I set up shop in a friend's borrowed caravan.  He assured me that the caravan was equipped with a cake pan and an oven, so all I needed to do was purchase ingredients.  In the name of simplicity (and because I was working with a loaf tin), I opted for a recipe by Ina Garten for lemon yogurt cake.  A lemon drizzle cake is an easy option for baking in a loaf tin, but the idea to use yogurt was inspired by the delicious natural Llaeth y Llan I'd picked up the day before.  Mixed with a bit of jam and muesli and you'll almost forget about cake... just kidding.  It's good, but nothing is that good.

This was my first go at making a cake with yogurt, and it was also the first time I opted to use self-rising flour.  I did so with much trepidation.  With self-rising flour you simply don't have the same control over your ingredients that you do when adding the rising agent or agents yourself, but since baking powder alone would have cost as much as the flour, and there would have been far more of it than I needed for my Pop-up Tŷ, I picked up the self-rising flour and popped it in the basket.

In the end I altered Ina's recipe in part intentionally, in part incidentally (the self-rising flour) and in part accidentally.  My version can be found in the Recipe Box.  Note the addition of a raspberry swirl (intentional) and the removal of salt (accidental).  Because I used butter and not oil, as called for in the original recipe, I also changed the method.  I began by creaming the butter and sugar together, which I hoped would also give the cake an extra boost if the self-rising flour failed.  Creaming creates tiny air pockets in the butter, which adds volume to the cake.  I don't know if it actually had any hand in the success of the raising of this particular cake, however, as I left the bowl too close to the hot oven and the butter began to melt fairly rapidly.  Next I added the zest, and then beat in the eggs followed by the yogurt.  Finally, combine the self-rising flour with this mixture.

Pour one third of the batter into the prepared tin; I lined the tin with parchment in addition to greasing it, but simply greasing and flouring it is an option.  On top of this layer, dollop about a tablespoon or so of raspberry jam.  I tried to dollop it in a pattern that I thought would enhance the swirl, but it's not necessary (and perhaps not effective...).  Pour a second third of the batter on top of this layer, and repeat the jam process.  Top it off with the final third of batter.

After all the batter was in the tin, I swirled a skewer through it.  This process did create a bit of a swirl, but the technique needs perfecting.  While the cake is baking, prepare the drizzle by measuring out approximately 1/3 cup of confectioner's sugar and mixing it with the juice of your lemon.  I used the juice of about one half of the lemon; the drizzle should be runny, but you also do not want it to be too thin if you want it to drip nicely and hang on the cake.

Despite my apprehensions, the self-rising flour seemed to do a fine job of raising the cake.  The caravan oven also produced a nice result; any unknown oven can turn out to have unexpected quirks, but this one seemed to be a steady worker and didn't cause any problems with the bake.  I wish I could say the same for my dormitory oven, but that's a story for another time...  I also learned something new at this Pop-up Ty: the Gas Mark is indeed a scale that people use (it was a first for me!), and if you want to bake a cake, chances are you'll want to be set to mark 4 - maybe mark 3 if you're taking the low and slow approach.

A Pop-up Ty, a car delivery through the windy roads of Wales, fire in the pub, and no trafferth... Iechyd da!

Pie in July

This isn't National Cake Week, and today wasn't Pi Day, but I went ahead made a pie this morning anyway.  Because pie is delicious.  Also because it was the 4th of July and it seemed appropriate.

Strawberries and blueberries are in season (not to mention conveniently coloured) so I decided to make a strawberry-blueberry pie.  I used recipes from Joy of Baking and Martha Stewart as guidelines, and my recipe is in the Recipe Box.  It was really very tasty, but to say that it was runny would be an understatement; it was fruit soup on the inside.  I don't know if it hadn't had enough time to set when I cut into it, or if it needed more tapioca or cornstarch, but it would be worth adding more tapioca or cornstarch, or both... I was delighted, however, to find that despite all the juices there was no soggy bottom!  I think baking on a hot sheet might make quite the difference.

I used 1 1/2 times Martha's recipe for pâte brisée, and I was as happy with it this time as I was the last time.  There is probably more cutting to this pie than anything else, and it begins with the pâte brisée.  Chop up cold butter and cut it into the flour and salt mixture until it resembles a coarse meal.

Add 1/4-1/2 cup ice water to the dough just until it sticks together.  Split the dough in half to form two disks, cover them, and chill them in the refrigerator for at least an hour (I left mine overnight).  When it's ready roll one disk to about 1/8" thick and place it in a 9"-10" pie dish.  Spread a thin layer of butter over the bottom of the shell - this will form a barrier between the filling and the crust to prevent a soggy bottom - and return to the refrigerator.  Roll out the second disk and return it as well.

I made a new-to-me discovery while getting ready to make this pie: tapioca is 'ground arrowroot' in the UK.  At least I think it is.  While the tapioca my mom uses to firm up her pies is not ground, tapioca starch is the only ingredient in ground arrowroot so it seems to be the right thing.  I decided to give it a try anyhow.

Whisk the sugar, cornstarch and tapioca together and set it aside while you hull and cut the strawberries.  When the strawberries are all sliced up, mix them in a big bowl with the blueberries, and then stir the sugar mixture into the berries.  Let the berries sit about fifteen minutes, and while they're doing that take the disk of dough back out of the refrigerator and cut it into 1" strips.  When that's done, remove the pie dish, and pour the berries in.

Form a lattice on the pie, starting by laying half of the strips over top of it.  Fold back alternating strips, and lay another strip perpendicular over the remaining strips.  Unfold the folded strips back over the perpendicular strip.  Repeat until the lattice is complete.

Nearly lastly, beat an egg and brush it over the pastry, and then dust it with sugar sprinkles.  None of this step is necessary, of course, but it looks pretty and the sugar adds a nice crunch.

Then pop it in the oven!  Make sure, especially if you decide not to bake the pie on a baking sheet, that you cover the bottom of the oven with tin foil.  The pie will drip, and it will be a sticky mess.  A tasty, sticky mess.

And the best part?  This red, white and blue pie can do double duty: preheat your oven for Bastille Day, July 14th.