Preheat the oven to 350°F and grease a 9x13-inch baking dish. Set aside.
Heat 1 tbsp of oil in a large skillet over medium heat, then cook the sausage until browned. Transfer the sausage to the prepared baking dish.
2 tbsp olive oil, 1 lb chicken or turkey sausage
Using the same skillet, add in the other 1 tbsp oil, and sauté the peppers and shallots until softened (about 4–5 minutes). Add them to the baking dish with the sausage.
1 red bell pepper, 1 green bell pepper, 2 small shallots, 2 tbsp olive oil
In a blender, or using a large bowl with a hand blender, blend together the eggs, egg whites, cottage cheese, salt, pepper, garlic powder, and onion powder until smooth and combined (about 10 seconds).
10 egg whites, 16 oz cottage cheese, 1 tsp salt, ½ tsp pepper, ½ tsp garlic power, ½ tsp onion powder, 2 whole large eggs
Pour the egg mixture over the sausage and vegetables, then sprinkle the cheese evenly on top. Gently stir everything together so the ingredients are evenly distributed.
1 cup shredded cheddar or gruyere cheese
Bake for 35–40 minutes, or until the egg casserole is set in the center and lightly golden on top. Let cool for 10 minutes before slicing and serving.