1 lg. onion, chopped & lightly browned with 1 lb. hamburger in same skillet
1 or 2 cans kidney beans
1 can mushroom stems & pieces
1 lg. can tomato paste or sauce

Simmer all ingredients together 10 to 15 minutes. Pour mixture into a casserole dish. Add 3 cups cooked macaroni, top casserole with plenty of grated cheese. Bake in 350 degree oven until cheese is lightly brown and casserole is bubbling, about 1/2 hour.