Pepper`s Tuna Casserole

6 1/2 oz Water-packed tuna

1/2 c Onion; diced

6 oz Egg noodles

1 cn Light cream of mushroom soup

No Salt; to taste -Pepper; to taste 2 sl Light sandwich cheese

Cook noodles; drain. Mix in all ingredients and top with the cheese. Bake at 350 degrees for about 45 minutes to 1 hour.