5 Tbsp. cold, unsalted butter, cut into 1/4-inch pieces
4 Tbsp. cold vegetable shortening, in Tbsp.-size pieces
1/4 cup ice-cold water
Combine flour, sugar, and salt in the bowl of a food processor. Pulse the machine once or twice, to mix. Scatter the butter over the flour. Pulse 4 or 5 times, breaking the butter into coarse pieces. Add the shortening and pulse again, 4 or 5 times, until the fat is cut into small, pea-size pieces.
Remove the lid and sprinkle the water over the flour mixture. Pulse again, repeatedly, just until the mixture forms large crumbs that clump together (the dough should not ball up around the blade).
Dump the crumbs onto your work surface and pack them together like a snowball. Place on a long piece of plastic wrap; flour the dough lightly, then flatten into a disk about 1/2-inch thick. Wrap in the plastic and refrigerate 1 to 2 hours before rolling. Makes a single crust for a 9- to 9-1/2-inch deep-dish piecrust; make the recipe twice for a double-crust pie.