Spam and Cheese Casserole

1 can cream of celery or mushroom soup
1 can spam or ham (12 ounces)
1 cup cooked macaroni
1/2 cup grated cheese

Cook onion in 1-tablespoon butter; add cream of mushroom soup, pour in casserole dish and add macaroni. Then place sliced or chunked spam on top and cover with grated cheese. Cook at 350 degrees for 30 minutes.