Dice the butter and return it to the refrigerator while you prepare the flour mixture.
Place the flour, salt, and sugar in the bowl of a food processor fitted with a steel blade and pulse a few times to mix.
Add the butter and shortening. Pulse 8 to 12 times, until the butter is the size of peas.
With the machine running, pour the ice water down the feed tube and pulse the machine until the dough begins to form a ball.
Dump out on a floured board and roll into a ball. Wrap in plastic wrap and refrigerate for 30 minutes.
Cut the dough in half.
Roll each piece on a well-floured board into a circle, rolling from the center to the edge, turning and flouring the dough to make sure it doesn't stick to the board.
Fold the dough in half, place in a pie pan, and unfold to fit the pan.
Repeat with the top crust.
