We had this frequently when we lived in Germany. When we returned to the US, I made it but haven't had it for years. I put thin sliced onion in with the potatoes. Heavily butter a 7" cast iron skillet, and put the potato into that, patting it down firmly with a spatula. Let it cook, on the burner, about 10 minutes or so (can't remember exactly). Flip it out of the skillet onto a plate, put a lot more butter into the skillet (no wonder it is so good!) then slide the potatoes off the plate back into the skillet to finish cooking. It should be brown and crispy on the outside, but buttery soft in the middle. Serve with schnitzel and salat. I see this on my menu for next week! Thanks, Mike!