Stir together flour, salt and sugar in a large bowl. Cut in cold butter with a pastry cutter (or use your hands!) until crumbly — the butter should be in roughly pea-sized chunks. (FOOD PROCESSOR: combine flour, salt, sugar by pulsing a few times. Add in butter cubes and pulse until crumbly)
Stir in 2-3 tbsp cold water and work dough with your hands until it comes together in a ball, adding in additional ice water if necessary. (FOOD PROCESSOR: Add water and pulse until dough starts to form a ball, then press dough together into a ball)
Shape into a fat disc and wrap in plastic wrap. Refrigerate for at least 1 hour or up to 1 week.
Roll out pastry on a large piece of wax paper — make sure it isn't too thin.
Cut dough into 3-3.5" rounds using a circle cookie cutter, large cup or small bowl.
Place rounds into a muffin pan, gently pressing the pastry into the bottom of the cup and up the sides. If you knick a hole in it, use your finger to press the pastry back together. You will fill one 12-cup muffin pan.
Place muffin pan into the freezer for 10-15 minutes.
