Pulse the food processor until the butter is broken up and the mixture is crumbly.
Turn on the food processor and drizzle in the water. Add just enough water to make a crumbly dough. If you add enough water for the dough to come together into a ball, you will have dough that is way too wet and will be tough.
Separate the dough and form into two disks. Wrap them in plastic wrap and chill in the fridge for 30-60 minutes before using.
Video
Notes
For a pie that calls for a baked pie crust, use one dough disk.