- Clean the leek and cut into fine rings. Sauté in the melted butter. Now deglaze with the broth and bring to the boil. Simmer for 10 minutes, then remove 4 tablespoons of leek and set aside.
- Puree the rest and stir in 2/3 of the cheese with the crème fraiche. Season to taste with the spices. Add the prawns and the rest of the leek to the soup and heat.
- Arrange on plates and sprinkle with the rest of the cheese.
- Serve with baguette.