Make crust: Add flour, salt, and butter in food processor. Pulse in short bursts, 5 to 6 times, until butter is distributed throughout flour in small pieces. With processor on low add water, 1 tablespoon at a time. Pause at 5 tablespoons and allow dough to begin to come together in center of bowl. Continue to add water until dough forms a ball. Gather dough ball and transfer to flat surface. Form into a disk, cover with plastic wrap, and place in refrigerator for 30 minutes.