Stir together 1 1/2 cups flour and 1/4 tsp. salt. Cut in 1/4 cup cold shortening and 4 Tbsp. cold unsalted butter until crumbly. Mix in 3 Tbsp. ice water with a fork. Knead once or twice. If dough is too dry to form a ball, sprinkle with 1 Tbsp. water and knead. Form into a disc, wrap in wax paper and refrigerate for 20 minutes. (Pastry can be frozen for up to 1 month.) Yields 1 (9-inch) pie shell.