Doug, you were approaching one of the classic French Recipes, Pommes de terre duchesse! It usually starts with one pound peeled boiled potatoes rubbed through a sieve. Put the puree in a saucepan, dry off for a few moments, on the heat, turning with a wooden spoon; add 3 tablespoons butter, season with salt, pepper and a little nutmeg (or how you like potatoes seasoned), bind with one egg and mix. Chefs often use it for garnish around a main dish, etc. But if you make into croquettes (patties) and brown lightly, they are damn good. The chefs use yellow potatoes.