2/3 cup unsalted butter, very cold, cut into pieces
Preparation
Place the flour, salt and 1/4 cup sugar in the bowl of a food processor. Blend for a few seconds. Add the butter and blend, a few seconds at a time, until the mixture has a grainy texture. Add ice water and vinegar. Mix again a few seconds at a time, adding a little water if necessary, until a ball begins to form.
Remove the dough from the bowl and form two balls with your hands. Dust with flour and wrap the balls individually in plastic wrap. Refrigerate for 30 minutes.
Place the rack at the bottom of the oven. Preheat the oven to 400°F ( 205°C).
Put some butter in a pie plate. Roll out the two balls of dough and darken a 23-cm (9-inch) pie plate with a crust. Put in the oven for 10 minutes. Make an incision in the center of the second pie shell and set aside.
In a bowl, combine blueberries, sugar, brown sugar. Let stand for 10 minutes.
Once the bottom of the pie is baked, put the blueberry mixture and add a teaspoon of butter in the center of the pie (on top of the mixture).
Cover with the other dough layer. Seal the dough well by crushing the rim with a fork or your fingers. Brush with egg white.
Bake at 375°F for about 30 minutes (until golden brown). Let cool. Serve with vanilla ice cream.
