To make the crust by hand, add the butter, flour, salt, and sugar into a large bowl and work it together with a pastry cutter until you have coarse crumbs. Pour in the egg, water, and vinegar and stir until just combined and you can bring the dough together into a ball. Avoid overworking the dough.
To make the crust in a food processor, add the butter, flour, salt, and sugar to the food processor and process until you have coarse crumbs. Add the egg and drizzle the water and vinegar into the food processor chute while it is running. Be careful not to overwork the dough. Turn off the food processor as soon as it seems to be holding together and you can press the dough together to make a ball.
Separate into 2 balls of dough, press each into a disc about 2 inches thick, and place in freezer bags.
Place each bag in the freezer. You'll only need one ball of dough for this pie, the second should keep in the freezer for 6 months or more.
Remove one ball of dough after 20 minutes in the freezer and roll it out on a floured surface into a 10 inch circle.
Place the dough in the pie pan and tuck the edges under to make a neat, thick crust around the edges.
Crimp the edges with your fingers or a fork.
Place in the refrigerator until ready to fill.