Dice the potatoes and cook them in the stock. Cut the wammerl into cubes and the leek into rings. Fry the Wammerl in a pan, then sweat the leek a little. Puree the potatoes, if the soup is too thick, just add a little more water and season with salt, pepper and nutmeg. Add the jellyfish with the leek. Cook until the leek is soft. Finally add the sour cream.
Tip: You can also cook a few carrots with the potatoes.