Combine butter, cheese, and dry ingredients in the bowl of a food processor, and pulse until the butter is pea-sized or smaller. Pulse the food processor rapidly while adding the water. Do not over-mix.
Turn the dough out onto a length of plastic wrap, and compact it into a flat square 8 x 8 x 1-inch high. Wrap the dough tightly in the plastic and refrigerate for 1 hour before rolling.
Yield: 30, 3-inch galettes
