Place the flour, salt and sugar in a food processor and process until combined. Add the shortening and process until the mixture is the texture of coarse sand, about 10 seconds. Drop the butter pieces into the machine and process again until the mixture resembles coarse crumbs, with butter bits no large than small peas, about ten 1-second pulses. Transfer to a medium bowl.
Fold 4 tablespoons of the ice water into the flour mixture. Combine just until a dough forms. Add another tablespoon of ice water if needed. Flatten dough into a 4-inch disk, wrap in plastic and refrigerate for at least 1 hour or up to 2 days.
Remove the refrigerator (if refrigerated more than 1 hour, allow to stand on the counter top until malleable). Working on a lightly floured work surface, roll the dough to a 12-inch circle. Transfer the dough to a 9-inch pie plate by rolling the dough around the rolling pin and unrolling it over the pan. Lightly press the dough into the pan corners. Trim the dough edges to extend about 1/2 inch beyond the rim of the pan. Fold the overhang under and flute the dough edges using the index finger of one hand the the thumb and index finger of the other. Refrigerate until firm, about 40 minutes, then freeze until very cold, about 20 minutes.
Adjust an oven rack to the lower-middle position and heat the oven to 375 degrees. Remove the pie dough from the freezer and press a doubled 12-inch piece of heavy-duty foil inside the pie shell. Fold the edges of the foil to shield the fluted edge. Distribute 2 cups ceramic or metal pie weights (or dry rice) over the foil. Bake until the dough looks dry and is light in color, 25 to 30 minutes. (Meanwhile, prepare the Pie Filling by following the instructions below.) After the pie shell bakes 25 to 30 minutes, carefully remove the foil and weights, then continue baking until light golden brown, 5 to 6 minutes.