How to cook
Peel the potatoes and cut them into round slices. In an oven dish, generously smeared with butter, arrange half the potatoes.
Put the remaining potatoes on top, along with the rest of the butter and milk, if any remains. Bake 1 hour at 356°F (180 °C).
Remove from the oven, cover with a towel and let it smother for 20 min. Serve immediately after.