STIR together frozen peas and chopped celery, with cream of mushroom soup and milk in a large microwaveable dish. Microwave on HIGH for 10 minutes or until vegetables are tender.
ADD tuna, macaroni and 1 cup (250 mL) cheese to vegetable mixture.
SPRINKLE with remaining cheese and microwave on HIGH for additional 10 minutes or until hot and bubbly.
