2 tbsp. butter
1/2 c. chopped onion
1 can condensed cream of mushroom soup
1/2 c. milk
2 c. medium egg noodles (cooked)
1 c. cooked peas
2 cans tuna
1/2 c. shredded cheese

In 2-quart saucepan over medium heat in hot butter cook onion until tender. Stir in soup, milk, noodles, peas and tuna. Pour in casserole dish. Bake at 400 degrees for 25 minutes or until hot. Top with cheese. Bake 5 minutes more or until cheese is melted.