Cook the potatoes. Make a puree.
Do not drain the water into the pan!
Finely chop the onion in a bowl and fry in butter.
Cut the sausages into slices.
When the onion is browned, add the sausages.
Fry until golden brown.
Beat the egg in a glass until smooth.
In boiling potato water, add potatoes, onions + sausages.
Pour in the egg, stirring the broth continuously.
Season with salt and pepper.
Boil for a few minutes.