Prepare the Crust:

1. Sift almond flour and xanthan gum into a bowl. Add sourdough starter and butter. Mix together until combined.
2. Place dough in the refrigerator for 30 minutes to firm up.

Prepare the Bacon:

3. While dough is chilling, fry bacon until crispy. Drain on paper towel and set aside to cool. Once cooled, crumble the bacon.

Par-Bake the Crust:

4. Preheat oven to 400°F with rack in lower-middle position.
5. Spray a quiche baking dish with avocado or olive oil spray.
6. Place chilled dough ball in the middle of the dish. Using wet fingers (wear gloves if desired), press the dough outward toward the edges and up the sides to create a ledge at the rim.
7. Par-bake the crust for 15 to 20 minutes, watching closely as almond flour can burn quickly. Remove when the dough is cooked but not yet golden. Let cool completely.

Prepare the Filling:

8. While the crust is par-baking, whisk together eggs and cottage cheese in a blender until smooth. Transfer to a bowl.
9. Fold in crumbled bacon, shredded cheddar, and chopped scallions. Season with pepper (and salt if desired). Refrigerate until needed.

Bake the Quiche:

10. Reduce oven temperature to 350°F.
11. Pour the egg mixture into the cooled par-baked crust.
12. Bake uncovered for 25 minutes. Cover with foil and bake for an additional 20 to 30 minutes until the center is firm.
13. Let cool for 10 minutes before slicing and serving.