Process flour and salt in a food processor. Scatter butter over flour; pulse until mixture resembles coarse cornmeal, 7–12 pulses. Drizzle 3 tablespoons of water over flour mixture. Pulse until mixture resembles wet sand and forms a dough when pinched, 5–10 pulses. (If the dough is too try, add additional water by teaspoon until a dough forms when pinched.)
Transfer to a large piece of plastic wrap and gently form dough into a ball; wrap in plastic and flatten into a 5-inch disk. Refrigerate dough until very firm, at least 1 hour.
Generously flour a work surface. Unwrap dough and lightly dust with flour. If needed, let dough stand at room temperature until it gives slightly when pressed; 5–10 minutes. Roll dough out into an ⅛-inch thick 13-inch round.
Fold dough in quarters; place corner in center of a 9-inch pie plate. Gently unfold dough to cover plate, using one hand to pick up edges of dough and an index finger to press dough into corners and up sides. Trim dough overhang to ½-inch. (Use dough trimmings to patch any thin creased areas caused by folding).
Tuck edges of dough under and crimp using thumbs and pointer fingers.
Freeze dough-lined pie plate for 20 minutes. Prick bottom, sides and corners with a fork. Line dough with a piece of foil, pressing it flush against the corners, sides, and to cover the rim. Prick foil about a dozen places with a fork. Freeze shell for 30 minutes.
Heat oven to 400ºF (204ºC) with rack set in lowest position. Bake shell 25 minutes, pressing down on foil with an oven mitt to flatten if it puffs. Remove foil and continue to bake shell just until it begins to color, about 10 minutes.