1/4 c. chopped onion
1 tbsp. butter
1 can Campbell's cream of mushroom soup
1/2 c. milk
3 c. cooked elbow macaroni
1 1/2 c. shredded cheddar cheese

In saucepan, cook onion in butter until tender. Blend in soup and milk; add macaroni and cheese. Heat until cheese melts. Makes about 4 cups.