Ham Rolls Stuffed With Broccoli Mac And Cheese

1 ⅓ cup dried elbow macaroni 3 cup chopped fresh broccoli 1 tablespoon butter ¼ cup finely chopped onion 4 teaspoon all-purpose flour ⅛ teaspoon ground black pepper 1 ¼ cup fat-free milk 1 cup shredded reduced-fat cheddar cheese (4 oz.) 4 ounce American cheese slices, torn (about 5 slices)