Macaroni And Cheese Casserole - cooking recipe

Ingredients

8 oz. elbow macaroni, cooked and drained
1 small onion
1 can cream of mushroom soup
2 (12 oz.) pkg. grated cheese
1 c. mayonnaise

Preparation

Preheat oven to 350\u00b0.
In a casserole dish, combine all ingredients.