Combine Flour and Olive Oil in mixing bowl and combine until the mixture is crumbly.
Add Starter and Milk. Combine until it becomes a cohesive mass of dough.
Cover and let sit on counter overnight. (note: I use Almond milk since it's sitting out overnight).
Same Day Instructions
Mix the flour, salt, baking soda, and baking powder in a large mixing bowl. Go ahead and preheat the oven to 400 degrees F.
Add oil or butter and cut into the flour mixture until crumbly.
Mix in the sourdough starter and milk until just combined.
Proceed to the shaping directions.
The next morning in a small cup, add the salt, baking powder, and baking soda.
Preheat oven to 400 Degrees F
Dimple the dough and sprinkle the salt mixture over the top. Take a spatula and turn the dough over itself until it's combined.
Shaping
Move dough to a lightly floured surface and turn the dough a few times to make sure all ingredients are well incorporated.
Roll dough out to 1/4 to 1/2 inch thick and cut out 8 equal biscuits. I use a biscuit cutter, but, you can use a mason jar top.
Add to cast iron skillet.
Bake for 20-25 minutes or until golden brown.
Notes
Store biscuits at room temperate in a plastic bag for up to 3-4 days.Store in freezer for up to 3 months after baked and reheat in the oven at 325 degrees F for 10-15 minutes until warmed through.