Cook macaroni according to package directions; drain.
In a 2-quart casserole combine macaroni, broccoli, ham, and green or red pepper; set aside.
For sauce, in a small saucepan stir together milk, cornstarch, and pepper. Cook and stir till thickened and bubbly. Add cheese; stir till melted. Stir sauce into mixture in casserole. Combine bread crumbs and margarine; sprinkle atop mixture in casserole.
Bake, uncovered, in a 350∞ oven for 30 minutes or till bubbly and bread crumbs are lightly browned.
Microwave directions: Prepare as above, except use a microwave-safe casserole and do not sprinkle bread crumbs over macaroni mixture before cooking. Micro-cook macaroni mixture, covered, on 100% power (high) for 6 to 8 minutes (9 to 10 minutes in a low-wattage oven) or till hot, stirring once. Top with bread crumb mixture. Cook, uncovered, on high 1 minute more.
