Cook macaroni according to package directions; drain ... rinse. Combine macaroni, cheese, soup, and mayonnaise. Mix well. Stir in mushrooms, onion, pimento, green pepper, ... minutes, or until bubbly.
Cook onion in 1 tablespoon butter; add cream of mushroom soup, pour in casserole dish and add macaroni. Then place sliced or ... cover with grated cheese. Cook at 350 degrees for 30 minutes.
Ingredients: 4 (cheese .. ham .. macaroni .. soup)