2 c. cooked macaroni
1 lg. green pepper
3/4 c. onion
3 c. mild Cheddar cheese
3/4 lb. Velveeta cheese
1/2 c. pimentos, drained
1 1/4 c. Hellmann's mayonnaise
1 lg. jar mushrooms pieces

Mix all together in large bowl. Pour into 2 (9x13 inch) dishes or cut recipe in half. Crumble Ritz crackers with melted butter on top. Bake at 350 to 400 degrees until bubbling.