Sauté bacon and shallots in a saucepan. Add leek and potatoes and let them color slightly.
Add the sauerkraut, clear soup and whipped cream and simmer for 30-40 minutes with the lid on.
Blend the soup in a hand mixer or with a hand blender and pass through a sieve. Season with salt, pepper and nutmeg, bring to a boil.
Distribute eel cubes evenly in soup bowls. Hot soup over it form and bring to table sprinkled with parsley.