I found this recipe in a Kraft Food & Family magazine and adapted it slightly to fit our tastes. I decreased the amount of beef stock and added the W sauce to make it slightly richer and thicker. DBF ate 2/3 of the pan the first time I made this, so it is definitely a hit around here. For faster prep, use leftover mashers. You could probably also use potato flakes, but I don't like those so I haven't tried it that way. DBF likes to eat his pie with HP sauce; I like it the way it is.