Preheat oven to 350 F. Grease a quiche baking dish or 8x8/9x9/7x11-inch glass baking dish with non-stick cooking spray or olive/coconut oil spray.
Brown the sausage (or chorizo). Drain well and add to the bottom of the prepared baking dish.
In a large mixing bowl, whisk together the eggs, coconut milk, green chilies, minced onion, garlic powder, ground cumin and some salt and pepper.
Pour the egg mixture over the sausage in the baking dish. Then float the bell pepper slices into the eggs.
Bake in the preheated oven for 30 to 35 minutes, or until toothpick comes out clean in the center.
Serve Southwestern Frittata with avocado slices and salsa.