Overnight Tuna Casserole

Ingredients
- 1 can cream of celery soup
- 1 c milk
- 1 6 12 oz can water-pack tuna drained
- 1 c uncooked elbow macaroni
- 1 c frozen green peas
- 12 c chopped onion
- 1 c shredded Cheddar cheese
Directions
- Reserve 14 cup Cheddar cheese
- Whisk soup and milk in 2-quart microwave-safe bowl until well blended
- Stir in remaining ingredients except reserved cheese
- Cover and refrigerate at least 12 hours or overnight