Stir the soup, milk, broccoli, carrots, beans, chicken, black pepper, 1/2 can onions and red pepper, if desired, in a 1 1/2-quart casserole. Bake at 350 degrees F for 25 minutes or until the chicken mixture is hot and bubbling. Stir the chicken mixture.
Sprinkle the remaining onions over the chicken mixture. Bake for 5 minutes or until the onions are golden brown.