For the Crust

2 1/2 cup all-purpose flour
2 tablespoons sugar
3/4 teaspoon salt
1 cup (2 sticks) unsalted butter, cold, cut into cubes
1/2 cup cold buttermilk

For the Strawberry Filling

5-6 cups fresh strawberries, hulled and sliced in half
1/2 cup granulated sugar
1/3 cup lightly packed brown sugar
1/4 cup cornstarch
large pinch of salt
2 tablespoons fresh lemon juice
heaping 1/4 teaspoon ground ginger
1 large egg, beaten and granulated sugar for topping the unbaked pie