Heat the oil in a pan. Sauté the onion and garlic for approx. 1 min. Add the tomato puree and tomatoes, pour in the stock, cover and simmer for approx. 12 mins., puree.
In a bowl, mix the meat with all the other ingredients up to and including the pepper. Knead the mixture well, shape into 16 balls. Heat a dash of oil in a frying pan. Fry the meatballs in batches for approx. 5 mins. all over.
Plate up the soup, top with the crème fraîche, serve with the meatballs.