To make with a food processor, combine the flour, butter and salt in the bowl of a food processor. Pulse for 10 seconds and add the ice water. Pulse quickly 5 or 6 more times until the dough comes together. Remove the dough and place on a floured surface. Using your hands, work the dough into a ball and wrap in plastic wrap. Refrigerate for at least 30 minutes before using.
To make by hand, combine the flour and butter in a medium bowl, and mix with a pastry blender or your fingertips until the mixture resembles coarse crumbs. Add the water 1 tablespoon at a time and mix until the dough comes together and is no longer dry, being careful not to over mix. Form into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes before using.
Roll out on a lightly floured surface according to the recipe, then allow to rest again in the refrigerator before baking.