In a food processor, combine the flour and salt and pulse a few times to mix. Add the butter and shortening and process until the mixture is rough textured, with particles the size of peas.
Add 3 tablespoons of the ice water, 1 tablespoon at a time, pulsing briefly after each addition. Add another tablespoon of the water and pulse just until the dough begins to hold together. Add 1 more tablespoon of water if necessary.
Transfer the dough to a lightly floured surface and gather it into a ball, handling it as little as possible. Divide the dough in half. Pat the 2 pieces into disks, wrap in wax paper and refrigerate for at least 20 minutes or overnight before rolling out.