1/2 c. chopped onion
1/2 c. chopped celery
2 tbsp. butter
1 can mushroom soup
2 c. cooked macaroni or spaghetti (1 c. raw)
1/2 c. chopped canned tomatoes
1 can tuna, drained and flaked
1/4 tsp. oregano

In saucepan cook onion with celery and oregano in butter until tender. Blend soup; add remaining ingredients. Pour into casserole dish. Sprinkle with Parmesan cheese and bake until cheese is melted. Serves 4.