Put all the ingredients except for the egg yolks and water into a food processor and whizz until it looks just like breadcrumbs.
Add the egg yolks, pulse a few times to blend.
Drop by drop, Add the ice-cold water until the mixture comes together.
Put the dough into a surface with some flour and knead it quickly.
Chill for 1 hour after you pop into a plastic bag.
Put the cherries into a mixing bowl
Add the sugar a few at a time and taste. You can add more sugar if you need it.
Add the cornflour (cornstarch)
Add the juice
Leave to stand.
Preheat the oven to 160°C/325°F/Gas Mark 3.
Put some butter on a 20-cm (8-in) pie dish.
Remove the dough from the fridge and cut it in half.
Put some icing (confectioners’) sugar over the work surface. Roll half of the dough into a circle large enough to line the pie dish.
Line the dish with the pastry and heap the cherry filling on top.
Roll out the remaining pastry to a 20-cm (8-in) circle, then lay it on the top of the cherries. Press down the edges to seal.
Make a series of 5 or 6 small slits in the pastry, brush with water and sprinkle the demerara (turbinado) sugar over the top.
Bake in the hot oven for about 30 minutes, turning once, until golden brown. Leave to cool and serve with cream or ice cream.