Make the crust:
Step 1 - In a bowl, blend together the flour, butter and 1/2 teaspoon salt with your fingertips or a pastry blender until the butter is mostly combined with some pea-sized lumps. Using a fork, stir in 3 tablespoons of the water. Squeeze a handful of the dough, if it is still crumbly, stir in the remaining 1 tablespoon water. Gather the dough into a ball, then form it into a disk and wrap it in plastic wrap. Chill the dough at least 1 hour.
Step 2 - On a floured work surface with a floured rolling pin, roll the dough out into a 10-inch round. Using a round cutter, cut (4) 3 inch rounds from the dough. Chill the rounds until ready to use. Preheat the oven to 400 degrees F.