Using Pastry Cutter (bladed cutter not wire cutter) cut butter into flour mixture.
Don’t overwork it or let the butter get too warm. You should have little lumps of butter coated in flour and sugar. These bits of butter will flatten out when you roll it, leaving little pockets when cooked. This is what gives pastry its light, flaky texture. If the butter melts, you’ll end up with the consistency of al dente pasta.
Add the cold water and quickly form it into a dough. If the butter has gotten warm by this time, or if it’s especially warm in your kitchen, you might want to put the flour/butter mixture in the freezer for 10-15 minutes before adding the water and making the dough.
Once you’ve made the dough, transfer it to a one gallon zip-top bag and put in the refrigerator for at least a half-hour. You need this time for the water to soak into the flour. Otherwise it will just steam out when you bake it.
Take the dough out and roll it into a circle, still in the bag. Most one-gallon bags are just about nine inches across, which is exactly how big you want the crust to be. This also saves you from having to put flour on the table and rolling pin, and dealing with the cleanup afterwards.
After it’s rolled out, you can put it back in the refrigerator for two to three days, or freeze it and keep for several weeks.