2 cups peeled, cubed potatoes 1 large carrot, sliced 2 celery ribs, chopped 3 cups water 2 cups cubed fully cooked ham 2 tablespoons chopped green pepper 2 teaspoons finely chopped onion | 7 tablespoons butter, divided 3 tablespoons all-purpose flour 1 1/2 cups milk 3/4 teaspoon salt 1/8 teaspoon pepper 1 cup shredded Cheddar cheese 1/2 cup soft bread crumbs |