Peel the onions and cut into half rings. Put in a large saucepan with a little oil. Peel the potatoes, cut into cubes (put in a bowl). Peel off the skin of the Lyoner or meat sausage and cut the sausage into cubes.
Fry the onions and add the potato cubes and the Lyoner. Season with pepper, salt, sweet paprika powder and the tomato paste. Pour in water and bring to the boil briefly, then switch down.
Simmer for about half an hour (depending on the type of potato), stirring every now and then. At the end, add sour cream or creme fraîche.