2 cups flour
1/2 teaspoon salt
2/3 cups shortening
5-7 tablespoons of cold water + 1 teaspoon apple cider vinegar
heavy cream for brushing
6 cups blueberries
3/4 cup sugar
3 tablespoons flour
Grated zest and juice of 1 lemon
2 tablespoons cold butter
For crust: Stir together flour and salt. Using a pastry blender, cut in shortening until pieces are pea-size.
Sprinkle 1 tablespoon of the water mixed with vinegar over part of the mixture; gently toss with a fork. Push moistened dough to side of bowl. Repeat, using 1 tablespoon water at a time, until all the dough is moistened. Divide in half. Form each half into a ball. Refrigerate while you make filling.
For the blueberry filling: In a bowl, toss the blueberries with the sugar, flour, and lemon zest and juice.
On lightly floured surface, flatten 1 dough ball. Roll from center to edges into 12-inch circle. To transfer pastry, wrap it around the rolling pin; unroll into a 9-inch pie plate. Carefully place pastry into pie plate. Fill with blueberry mixture.
Tuck the pats of cold butter beneath the top layer of berries. Roll out the 2nd piece of dough and cover blueberries. Trim both to a 1/2-inch overhang around the pie. Tuck the overhang into a roll and crimp the edge, pressing down to hook some of the dough over the edge of the dish, holding the pie. Cut a hole in the center of the pie, as well as some decorative vents.
Brush the top of the pie with cream and dust it with sugar. Bake for 20 minutes. Reduce the temperature to 350 degrees F and bake for another 20 minutes. Cover the edges of the pie with foil and continue to bake until the center juices bubble and thicken, 25 to 35 minutes more.