Breakfast Casserole

Directions

1. In a nonstick skillet, cook sausage and onion over medium heat until sausage is no longer pink; drain and cool.
2. In a large bowl, beat the eggs, egg whites, milk, mustard, salt and pepper. Stir in the bread cubes, cheese and sausage mixture. Pour into a 13x9-in. baking dish coated with cooking spray. Cover and refrigerate overnight.
3. Remove from the refrigerator 30 minutes before baking. Bake, uncovered, at 350° for 35-40 minutes or until a knife inserted in the center comes out clean. Let stand for 5 minutes before cutting.