Tuna And Potato Casserole
["4 c. thinly sliced, pared potatoes", "3 Tbsp. butter", "1/4 c. flour", "2 Tbsp. prepared mustard", "2 c. milk", "1 tsp. salt", "1/8 tsp. pepper", "1 c. sliced onions", "1 family size can tuna"]
["Cook potatoes 10 minutes. Melt butter in double boiler. Stir in flour, then mustard. Add milk, salt and pepper. In greased casserole, arrange potatoes, tuna and onions alternately. Pour sauce and bake at 350\u00b0 for 45 minutes. Serves 6."]
["potatoes", "butter", "flour", "mustard", "milk", "salt", "pepper", "onions", "tuna"]