Fanny Farmer Fudge
["1 lb. butter", "1 can condensed milk", "4 1/2 c. sugar", "1 (12 oz.) pkg. chocolate chips", "walnuts (optional)"]
["Over medium heat, cook milk and sugar to boil.", "Stir for 15 minutes.", "Take off heat, add butter and chips and blend together. Walnuts optional. Pour into buttered 9 x 13-inch pan and let cool."]
["butter", "condensed milk", "sugar", "chocolate chips", "walnuts"]