In a large bowl, whisk together the flour and salt.
Cut in the cold butter until pea-sized pieces remain.
Add sourdough discard and drizzle in the ice water, mixing just until the dough comes together. If it looks dry, add another teaspoon or two of water.
Gather the dough, divide in half, shape into disks, wrap, and chill for at least 2 hours (or overnight).
On a lightly floured surface, roll one disk into a 12-inch circle.
Gently fit the dough into a 9-inch pie plate without stretching. Trim excess, tuck under the edges, and crimp or flute.
To blind bake: Chill the shaped crust 30 minutes, then freeze 15 minutes. Line with parchment and fill completely with pie weights or dried beans.
Bake at 400°F / 205°C for 15 minutes. Remove weights and parchment, dock the base lightly with a fork, then bake 10 minutes more at 375°F / 190°C until golden.
Cool completely before adding no-bake fillings, or proceed with a baked filling as directed in your pie recipe.