2 c. finely chopped ham
1 c. chopped onion
1/4 lb. butter
3 (10 3/4 oz.) cans cream of mushroom soup
4 c. grated cheddar and/or Countyline cheese
8 c. cooked macaroni
1 sm. can finely chopped mushrooms

Lightly brown onion and ham in butter. Stir in soup and gradually add cheese. Heat until cheese melts, stirring often. Cook macaroni for 7 or 8 minutes. (Do not overcook macaroni as it will finish in crock pot.) Drain macaroni thoroughly through colander. Combine cheese sauce with macaroni and pour into a 3 quart crock pot. Cook on low for 3 hours, stirring occasionally.