Using a food processor or a pastry blender, add flour, salt, cold butter and shortening (if using); cut until mixture resembles a coarse meal; small pieces of butter should still be visible.
Pour cold water over the mixture and work in by tossing with a fork until dough begins to form; use your hands as little as possible and work the dough as little as possible.
Divide dough into 2 balls, flatten into 2 rounds, wrap individually in plastic wrap and place in the refrigerator to rest for a minimum of 20 minutes.
The second round can be frozen and used another time.
The dough can also be made the previous day; take it out of the refrigerator for 10 - 20 minutes to warm slightly before rolling out.
Pre-heat oven to 400°F.
Roll the dough into a 12-inch circle and place in the bottom of a 9-inch or 10-inch pie plate.
Trim and flute the edges as desired; poke a few holes in the bottom of the pastry shell, rest in the refrigerator for an additional 20 minutes.
Place in pre-heated oven and bake for 12 – 15 minutes or until golden brown.
Remove from oven and cool completely before adding the filling.