Wash and brush the mussels and remove the beard threads if necessary. Sort out already opened mussels. Clean, wash and cut the leek into fine rings. Peel and chop garlic
Heat the fat. Sauté garlic and leek in it. Deglaze with 1 1/4 l water and wine. Bring to the boil, stir in stock. Cook the mussels for 5-10 minutes until the shells open. Remove the mussels, sort out closed ones
Pour cream into the stock, bring to the boil. Stir in soup paste and let everything simmer for about 5 minutes. Season to taste with salt, pepper and lemon juice. Heat the mussels in the soup. Garnish with parsley and lemon. Serve with roasted herb butter baguette