Tuna Noodle Casserole
["2 Tbsp. butter", "2 Tbsp. flour", "1 tsp. mustard", "2 c. milk", "salt and pepper"]
["Boil until thick.", "Put cooked noodles in a 4-cup Pyrex dish. Crumble drained tuna (two 5 ounce cans) over noodles.", "Pour the gravy over the tuna.", "Cover with potato chips.", "Bake 30 minutes at 350\u00b0."]
["butter", "flour", "mustard", "milk", "salt"]