In a large mixing bowl, whisk together flour and salt.
Cut in the cold butter with a pastry blender until mixture resembles coarse crumbs with small pieces of butter still visible.
In a separate small bowl, combine honey (or sugar) and sourdough starter. Add this honey/sourdough starter mixture to the flour and salt in the large mixing bowl. Stir until just combined. The dough should start to come together after adding the starter and honey, but it may be very dry. If it's too dry, add ice water a tablespoon at a time (up to 3-4 tablespoons of ice water) until the dough starts to stick together a little more.
Divide the dough into two pieces and wrap each piece with plastic wrap, forming each into a disk or square of dough. Put dough in refrigerator for at least 30 minutes, but 1 hour is better.
When you're ready to use the dough, remove from the refrigerator. Turn dough out onto a lightly-floured surface and roll one half out into a large circle about 12-14" in diameter.
Drape the bottom pie crust over the rolling pin and carefully transfer to a 9" pie dish. There will be some dough hanging over the edge of the pie dish. Fill the bottom crust with your filling, and then roll out the second crust and add to the top of the pie. Trim off the excess (I use my kitchen scissors for this), leaving about 1/2" excess dough all around the pie dish. Seal, crimp edges, and vent top pie crust.
Bake pie according to your recipe instructions.
Notes
Make sure all of your ingredients are very cold. I put my cubed butter into the freezer after cutting it into cubes. This step will ensure that your pie crust is very flaky.
You can use either sourdough discard or active sourdough starter.
I usually just use a pastry blender to cut my butter into the flour when mixing the pie dough, but you can also pulse the ingredients together in a food processor.
Sourdough pie crust may be made ahead and stored in the refrigerator for up to 3 days or frozen for up to 3 months. If pie crust is frozen, thaw overnight in the refrigerator before using.
You can use half whole wheat/half all purpose flour instead of just all purpose.
Depending on the consistency of your starter, you may need to add some ice water to help the dough come together. I recommend adding water (if needed) a teaspoon at a time (up to 3-4 tablespoons) until dough is moist enough to stick together.
Long-Fermentation Instructions
Cut cold butter into small cubes and set aside.
Whisk the flour and salt together in a large bowl.
Cut cold butter into the flour mixture until the pieces of butter are about the size of small peas.
Add honey and sourdough starter to the large bowl with flour, salt, and butter.
Mix until dough just starts to come together.
Cover the bowl and allow the dough to ferment for 8-12 hours. After the fermentation time, transfer to the refrigerator for a couple of hours before rolling out. You can also just put the bowl of dough into the refrigerator and allow it to ferment there for 8-12 hours or overnight.
Remove from the refrigerator, divide into two equal pieces, and roll out and use in your pie recipe.