This was usually served on Fridays during lent, but also anytime Mom needed a quick, stick-to-your-ribs, inexpensive meal.
In a big pot, bring some water to boil. Add some salt, then cook a package of Muellers wide egg noodles to the water. Bring back to boil and cook for another 8 minutes or so.
Drain noodles and set aside in the collander.
Make a roux: In the now empty pot, melt 4 tablespoons of butter. Once hot, add one small finely chopped onion in the butter until transparent. Drain one big can of tuna (Mom used chunk light; I prefer albacore). Chop up the tuna a little and then add to the butter and onion and heat through. Sprinkle with 4 tablespoons of flour. You could also add a cup of green peas here.
Little by little, each time allowing the mixture to heat, add 2 cups of milk to the roux mixture. As the mixture heats, it will begin to thicken and bubble. When its the perfect thickness for your tuna noodle casserole, remove from heat and stir in cooked noodles.
Take about 2 cups of potato chips and crunch them up into crumbs (the odds and ends at the bottom of the bags are good for this purpose.) Stir half of the potato chip crumbs into the noodle mixture., then poor into an ovenproof casserole. Cover the top with the remaining potato chips and dot with butter.
Bake for about 30 minutes at 350 degrees.
Serve with a salad and some good bread with butter.