Peel and roughly dice the potatoes and cook in salted water for 20-25 minutes.
Cut the onions into rings and fry them in a little butter until golden brown.
Heat the milk and 50 g butter in a saucepan. Drain the potatoes and carefully mash directly with the hot butter-milk mixture. Then season with a little nutmeg.
Remove the firm skin from the sausage bread slices and fry them in a hot pan with butter for about 2 minutes on each side. Do not fry too long or it will be too dry. The panes turn almost black.