What would a New England summer be without a slice of perfect blueberry pie?
Wash berries, remove stems, and gently stir with flour and sugar. Sprinkle with lemon juice to taste. Set aside.
Preheat oven to 400°. Unwrap the larger disk of Double-Crust Pastry Dough and place in the center of a large sheet of parchment paper. Cover with a second piece of parchment. Roll out, working from center, to a 13-inch circle.
Peel off top piece of parchment and transfer dough to a 9-inch deep-dish pie plate, peeled side down. Peel off remaining parchment and press crust into plate, draping any excess over the sides.
Unwrap smaller dough disk and place in the center of a large sheet of parchment paper. Cover with a second piece of parchment. Roll out, working from center, to an 11-inch circle. Set aside.
Pour berries into bottom crust. Distribute dots of butter over berries. Peel one sheet of parchment off top crust. Transfer top crust, peeled side down, to pie; then peel off remaining parchment.
Using a sharp knife, make three slashes in crust to let steam escape.
Fold bottom crust up over top crust and crimp to seal. Brush with egg wash; then bake until crust is golden brown and juices are bubbling, 40–50 minutes.
In a medium-size bowl, whisk together flour, sugar, and salt until well combined.
Sprinkle butter over f lour mixture, and use your fingers to work it in (rub your thumb against your fingertips, smearing the butter as you do). Stop when the mixture looks like cornmeal, with some pea-size bits of butter remaining.
Sprinkle 6 tablespoons ice water on top, and stir with a fork until dough begins to come together. If needed, add more ice water, a tablespoon at a time.
Turn out onto a lightly floured surface and knead three times, or just enough to make a cohesive dough—don’t overmix!
Gather into a ball; then divide into two pieces, one slightly larger than the other. Press each piece into a disk and wrap in plastic. Refrigerate 30 minutes.