Combine flour, salt and sugar in a food processor; pulse it one time to mix. Add the butter pieces and pulse 4 times. Add shortening one tablespoon at a time and pulse each time you add a tablespoon.
The mixture should resemble coarse cornmeal, with butter bits no bigger than peas. Sprinkle 6 tablespoons of ice water over flour mixture one tablespoon at a time.
Pulse once after you add each tablespoon of water. If you pinch some of the crumbly dough and it holds together, it’s ready. If the dough doesn’t hold together, keep adding water, a teaspoon at a time, pulsing once after each addition, until the mixture just begins to clump together.
Clean off your counter really well or use a pastry board or a nice cutting board. Flour your hands generously. Take the dough out of the food processor.
Make sure you refrigerate for at least an hour. Reserve the second disk for your next pie in the fridge. It can stay for up to 2 days in the refrigerator.
When it is time to roll the dough out, remove from the refrigerator. If the dough is too hard to begin rolling, let it rest a few minutes.
On a lightly floured surface, using a rolling pin, apply light pressure while rolling outwards from the center of the dough. Every once in a while you may need to gently lift under the dough.
You have a big enough piece of dough when you place the pie tin or pie dish upside down on the dough and the dough extends by at least 2 inches all around.
When the dough has reached the right size, gently fold it in half. Lift up the dough and place it so that the folded edge is along the center line of the pie dish.
Gently unfold and be sure to not stretch the dough to fit. Fold pastry into quarter folds and ease into plate, pressing firmly against bottom and side.
If the dough breaks up while you're laying it in the pie plate, no problem. Simply use your fingers to press it together. Make sure there are no cracks or holes in the dough.
Once you have laid the crust into pie plate, refrigerate again for about 15-20 minutes before adding the filling. The more it's chilled, the easier it will be to crimp the crust.