Whisk together the flour and salt in a large mixing bowl.
3 cups all-purpose flour, 1 ¾ teaspoons salt
Cut the shortening into ¼-inch thick slices and add it to the flour mixture. Using a pastry cutter or your hands, work the shortening in until the mixture has the texture of coarse sand.
⅓ cup vegetable shortening
Cube the butter by cutting a stick into fourths, and then slice it to make small cubes. Add it to the flour mixture. Work it in with a pastry blender or your fingers by breaking up the butter so that the mixture has the consistency of small peas.
13 tablespoons unsalted butter
Add 5 tablespoons of the ice water to the mixture and work it in just until combined. Add more ice water, 1 tablespoon at a time, until the dough holds together when you squeeze it.
8 to 12 tablespoons ice water
Turn the dough out onto a floured silicone baking mat or floured surface. Fold the dough into thirds. Then shape it into a circle.
Cut the circle of dough into two portions, with one slightly larger than the other. Pat each portion into a circular disc. Then roll the discs on their edges to smooth them out. Sprinkle more ice water on any dry spots.
8 to 12 tablespoons ice water
Wrap each disc in plastic wrap and refrigerate for 30 minutes, or up to 24 hours. Or, wrap in plastic wrap and put them in a zippered freezer bag or layer of aluminum foil, and freeze the dough for up to 2 months.
After the dough is chilled, remove the plastic wrap. Use a rolling pin to roll out the larger disc into ⅛ inch thick circle 13 inches in diameter.
Fold the circle of dough into fourths (fold it in half twice). Transfer the dough to a greased deep dish pie plate. Center the point of the folded dough in the plate, then unfold the dough. Press it into the bottom of the pan and up the sides, allowing some to hang over the edge.