1/2 c. chopped onion
2 tbsp. butter
1 can condensed cream of celery soup
1/3 c. milk
2 c. (4 oz.) noodles, cooked and drained
1 (6 1/2 oz.) can tuna, drained and flaked
1 (4 oz.) pkg. shredded Cheddar cheese
1/4 c. grated Parmesan cheese

Saute onion in butter. Add soup and milk. Stir in remaining ingredients except 1/2 cup Cheddar cheese. Pour into 1 quart casserole. Bake at 350 degrees for 30 minutes. Top with remaining Cheddar cheese and continue baking until melted. 4 servings.