First, make the pie dough. Whisk together the flour & salt in a large bowl. Working quickly, add the butter to the flour & toss. Use your fingers to press each cube of butter into a flat sheet. Keep tossing the butter to make sure each piece is covered in flour. If at any time the butter seems warm, refrigerate the bowl briefly. Sprinkle about 4 tablespoons of ice water into the bowl & use a gentle hand to stir together until just combined. You’ve added enough water to the mixture if you can pick up a handful of the dough & easily squeeze it together without it falling apart, but without it being all sticky. Split the dough into two disks, each wrapped in cling film & leave to rest in the fridge for at least 2 hours before using. (Remember, we need to keep the dough extra chilled if we want it to be extra flaky.)
Once the dough has chilled, remove one of the disks from the fridge & on a lightly floured surface, roll it out into a roughly 12-inch circle that is about ¼-inch thick. Carefully press the dough into your pie dish/tart tin & store in the fridge while you prepared the filling. (Think of the flakes.) (FYI: I fit one of the disks into my pie dish & left it to chill in the fridge overnight, ensuring that it was stone cold. I rolled the second disk into a circle & left on a sheet pan for perhaps an hour before filling & assembling my pie.)
Remove the second disk from the fridge & roll out into a circle roughly 12-inches. Place on a sheet pan & leave to chill in the fridge.
Now, the filling. In a large bowl, gently stir together the cherries, granulated sugar, cornflour, almond extract & lemon juice.
Fill the prepared pie shell with the filling & cover with the second prepared crust (or make into a lattice topping – I watched a tutorial on YouTube). Crimp the edges together, and leave to chill in the fridge until ready to bake (I left mine in the fridge pre-made and unbaked for 8 hours while I was at work).
Preheat the oven to 200C. While the oven heats up, slide the whole pie into the freezer for at least 15-minutes, & think of it as a necessary step to pie success.
When ready to bake, brush the top of the pie with the beaten egg yolk and sprinkle with some demerara sugar before baking for 40-50 minutes, or until the juices are bubbling & the crust is a deep golden brown.
Leave the pie to cool & serve warm with some lightly whipped cream.