Process flour, sugar, and salt in a food processor until combined. Add chilled shortening and pulse until coarsely ground. Add chilled butter and pulse until the mixture resembles coarse crumbles. Transfer to a large bowl.
Sprinkle 3 tbsp water over flour mixture. Using a rubber spatula, stir the mixture until dough forms. Form dough into a 4-inch disk, wrap tightly in plastic wrap and refrigerate for 1 hour or up to 2 days (dough can be frozen, wrapped tightly in plastic and aluminum foil, for up to 2 months. Thaw completely at room temperature being using)
Let the chilled dough soften slightly at room temperature, about 10 minutes. Roll out dough into a 12-inch circle. Transfer dough to 9-inch pie plate, fold the edge of dough under itself so the edge is flush with the outer rim of plate, and flute edges. Refrigerate for 40 minutes and then freeze for 20 minutes. Heat oven to 375 degrees.
Line chilled pie shell with 12-inch aluminum foil, folding foil over edges of the dough. Fill with pie weights and bake for 20 minutes. Remove foil and weights, rotate plate, and continue baking until crust is golden brown 7-10 minutes. Let cool to room temperature.