Pit flour, sugar and salt into the bowl of a food processor and pulse a couple times to mix.

Add about half of the butter to the food processor and pulse several times. Then add the rest of the butter and pulse 6 to 8 times until the largest pieces of the butter are about the size of large peas.

Sprinkle the mixture with about 1/4 cup of ice water and pulse again. Then add more ice water, a tablespoon at a time, pulsing once or twice after each addition until the dough just barely begins to hold together. When you pinch some of the crumbly dough together with your fingers, and it holds, it’s ready.

Empty the crumbly dough mixture from the food processor on to a clean, dry, flat surface. Gather the mixture in a mound. Divide the dough mixture into two even-sized mounds. Knead just enough to form each one into a disk, don’t over-knead. Sprinkle with a little flour, wrap in plastic, refrigerate for one hour or up to 2 days.

Remove two crust disks from the refrigerator, let sit at room temperature for 10 minutes in order to soften just enough to make rolling out a bit easier.

Melt the butter in a saucepan, low heat, stir in flour to form a paste. Add water, white sugar, brown sugar, and bring to a boil. Reduce temperature and let simmer. Preheat oven to 220 degrees C.

Roll out the doughs to two large circles that would cover the pie plate, on a lightly floured surface, add more flour if it’s sticking. Make one into a lattice work crust.

Place the bottom crust in the plate. Fill with apples, pour the sugar and butter mixture over the apples, cover with the lattice work crust. Brush egg yolk on top.

Bake 15 minutes in the oven, reduce the temperature to 175 degrees C, continue baking for 35 to 45 minutes, until apples are soft.