In the work bowl of a food processor, place flour, salt, dry mustard, paprika, and pepper; pulse until combined. Add cold butter and cheeses; pulse until mixture is crumbly, about 5 pulses. With processor running, add 1⁄4 cup (60 grams) ice water, 1 tablespoon (15 grams) at a time, just until dough comes together.

Turn out dough onto a heavily floured surface, and shape into a disk. Wrap tightly in plastic wrap, and refrigerate for at least 1 hour.