Peel and cut the potatoes in small pieces.
Boil the potatoes until they become medium soft.
Fry the potatoes in a frying pan with some of the butter until the dices have a soft brown surface.
Put the potatoes in a bowl on the side.
Cut the sausage and the onion in small dices, and fry in a frying pan.
When the sausage and onion are golden brown, add the potatoes and fry it all together for about 5 minutes.
Fry the eggs so the egg yellow still is a bit runny.
Serve it all warm together on a plate.