Heat the butter in a pan and fry the onion. Add the stock and sauerkraut and let it simmer for 15 minutes. Allow to cool and puree with the hand blender or blender. Rub through a sieve and stir in half of the cream. Season with salt and pepper.

Bring the remaining cream to the boil for the bacon foam. Set low and add the bacon. Let it simmer for 20 minutes. Pour the cream through a sieve and let cool. Put it in the fridge.

Pour the bacon cream into a kidde. Heat the soup and scoop into glasses or nice deep plates. Carefully spray the bacon cream on the soup and place a crispy dish on the edge of each plate. Garnish with vegetable shoots if necessary.