Combine flour and salt in a mixing bowl. Using a fork or a pastry cutter, cut vegetable shortening into flour until mixture resembles cornmeal. Next, begin working butter into the mix until it breaks down into pea-sized lumps. Sprinkle ice water over mixture, 1 tablespoon at a time, just until dough is moist enough to hold together when pressed into a ball. Press dough down into a disk, wrap with plastic, and refrigerate 45 minutes. Roll out and shape as needed.