Bring the broth to the boil, gradually stir in the cheese with a whisk. Cut the leek into rings, add and slowly simmer for about 15 minutes.

Knead the mince with the egg, onion, garlic and oat flakes, season with salt and pepper, add a little water if necessary. Form small balls out of them, fry in hot oil and degrease on kitchen paper.

Add the meatballs to the soup, stir in the crème fraîche and let it steep for a few more minutes. A fresh white bread with it and you are almost in heaven!