3 1/2 c. cooked elbow macaroni (cook about 1 3/4 c.)
1 (4 oz.) can mushroom stems & pieces, drained
1/4 c. finely cut pimento
1 1/4 c. cubed process American cheese
3/4 c. evaporated milk
3 tbsp. chopped onion
2 tsp. dry mustard
1 tsp. salt
1 tsp. Worcestershire sauce
1/4 tsp. pepper
4 slices process American cheese
4 thick tomato slices, if desired

Mix macaroni, mushrooms and pimento in a greased 2 quart casserole. Stir cheese, milk, onion, mustard, salt, Worcestershire sauce and pepper over low heat until cheese melts. Stir into macaroni. Top with cheese and tomato slices. Bake at 350 degrees for 25 minutes or until hot and bubbly.