For the Nordic fish soup, chop the soup vegetables and onion and sauté briefly in butter. Add the minced garlic and deglaze with white wine. Let it boil down briefly and then fill up with the fish stock. Add the same amount of water and let the soup simmer gently until the vegetables are cooked.
In the meantime, cut the fish fillets into bite-sized cubes.
Stir the lobster paste and crème fraîche into the soup and homogenize everything with a blender. Season to taste with salt, chili paste and lemon.Add the fish pieces to the soup and let steep for 15 minutes.
Cook the mussels separately to the soup.
Serve the fish soup with the mussels, or with slices of white bread lightly toasted with garlic butter.