Preheat & Prep. To start, preheat oven to 350 degrees F.
Make Tortilla Crust. Lightly grease a 9-inch metal pie pan with spray oil and line with 2 tortillas. They'll overlap some at the bottom, and won't perfectly cover the sides of the pan--this is fine!
Combine The Filling. In a medium mixing bowl, combine eggs, cottage cheese, spinach, basil, salt, and pepper. Mix with a fork to combine well, until evenly blended.
Assemble. Pour the filling into the tortilla crust and top with shredded cheese and tomatoes. (I put the tomatoes on cut-side up for prettier presentation!)
Bake in preheated oven for 32-35 minutes, or until the center is just set. (When you gently wiggle the pan, the center may have a slight wobble, but shouldn't look sloshy or liquid!) Let the quiche cool 10-15 minutes before slicing to let the filling finish setting up. (If you cut into it right away, it can be a bit too soft in the center to slice nicely!)
Serve & Store. Cut into 4 large wedges, or 6 smaller pieces and serve with your favorite hot sauce or chili crunch. Store leftover quiche in an airtight container in the fridge up to 3 days. Keep in mind that the crust will soften with time. Reheat leftovers in the microwave (or an air fryer, if you want a crispy crust!)