Preheat oven to 350°; spray 13 x 9-inch baking dish with cooking spray.
Heat large skillet over medium-high heat; spray liberally with cooking spray. Add pepper and onion; cook and stir 2 minutes or until crisp-tender. Add mushrooms; cook and stir 4 minutes or until moisture is released. Add sausage; cook and stir 5 minutes or until browned. Spread sausage mixture in prepared dish; sprinkle with bread and cheese. In medium bowl, whisk eggs, egg whites and milk; pour over bread.
Bake casserole 30 minutes or until internal temperature reaches
160°; let stand 8 minutes. Cut casserole into 16 pieces; serve topped with avocado along with hot sauce, if desired.
Serving Size 2 Pieces
Servings 0
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.