For crust, cut 1/4 cup butter into small pieces and freeze 1 hour. In a food processor, combine flour, 1 1/2 teaspoons sugar and 1/2 teaspoon salt; pulse a few times to mix. Add the frozen butter and the shortening. Pulse a dozen times until butter is the size of peas. Add ice water, one tablespoon at a time, until dough begins to form a ball. Gather pastry into a ball, kneading gently just until it holds together. Wrap in plastic wrap and refrigerate 30 minutes.