Classic Tuna Casserole

1 pkg 8 oz pasta, cooked according to instructions.
1 cup chopped celery
1/2 cup chopped onion
4 tbsp butter
4 tbsp flour
2 11-oz can condensed cream of mushroom soup
3/4 c milk
2 cans tuna, drained and flaked
1/4 cup grated Parmesan
1/2 cup broken potato chips

In a saucepan, cook celery and onion in butter till tender but not brown.  Stir in the flour; stir in condensed soup.  Gradually stir in milk.  Cook and stir til mixture is thickened and bubbly.Carefully stir in the tuna and the cooked and drained pasta.

Turn noodle mixture into a 9X13 pan.  Sprinkle Parmesan cheese over the top, and the broken potato chips over that. Bake, uncovered, in a 375 degree oven for 30 minutes.  Makes 12 servings.