2 1/2 c. cut up celery
2 (10 1/2 oz.) cans cream of mushroom soup
1 c. minced onion
1/2 c. water, more if needed
1 c. diced cheese
1 c. milk
2-3 (6 1/2 oz.) cans chunk tuna or 1 (13 oz.) can tuna
1/2 tsp. pepper
2 cans chow mein noodles OR 1 lb. cooked wide noodles OR 1 lb. cooked elbow macaroni

Combine all ingredients and pour into ungreased casserole. Sprinkle with parsley.