1 (8 oz.) box macaroni, cooked
1 sm. jar pimientos, drained
1 sm. jar mushrooms, drained and diced
1 can mushroom soup
1 c. mayonnaise
1/2 med. onion, grated
1/2 stick butter, melted
1 lb. grated sharp cheese
Ritz crackers

Mix cooked macaroni, pimientos, mushrooms, mushroom soup, mayonnaise, onion, melted butter, and grated cheese. Place in baking dish; top with crushed Ritz crackers. Bake at 325 degrees for 25 minutes or 15 minutes at 425 degrees.