1 (8 oz.) pkg. elbow macaroni
1 lb. grated Cheddar cheese
1 can cream of mushroom soup
1/2 c. mayonnaise
Little grated onion (optional)
Ritz cracker crumbs
2 tbsp. butter

Prepare macaroni as directed on package for casseroles. Don't over cook. Drain. Add cheese, soup, mayonnaise and onion. Stir well.

Melt butter and stir in with Ritz crackers. Top casserole with the Ritz crackers. Bake 235 for 35 minutes.