1. Combine the flour and salt. Using your hands, a pastry blender or a food processor, 'cut in' or pulse the chilled butter into the flour until the mixture resembles course meal.
2. Add the milk and combine until the dough comes together. Form into a flat cylinder and cover with plastic wrap. Chill for at least 15 minutes.
3. Lightly flour a work surface. Starting from the center, roll the dough to about 1/8 inch thick. Drape into a 9-inch tart shell or an 8-inch pie pan with the dough overhanging the rim. If using a tart shell, lightly brush the sides of the tart crust with cold water and fold the overhanging dough onto itself on the edge of the rim; trim. If using a pie pan, tuck the overhanging dough underneath itself on the edge of the rim and crimp.