Melt butter. Add flour, salt ... like gravy. Add soup and mayonnaise. Layer peeled and sliced potatoes and onions in dish. Pour ... 350°F for 75 minutes.
Preheat oven 425°F. Grease 13 ... stir together the soup and cheese. With a rubber spatula, fold in the potatoes and onions until thoroughly coated. ... 10 minutes before serving.