How to make
Cut off the heads, tails and bones of the fish and put them in a pot. Pour 5 cups (1.2 L) of water over them, season with bay leaf, black pepper grains, parsley and salt. Boil about 30 min. on low heat.
Boil water with bay leaf, parsley, a piece of lemon for about 20 min. Then place the molluscs in it and boil 10-15 more min. Then leave them to cool, along with the broth you boiled.
Meanwhile, heat the butter and braise the finely chopped onions in it, then add the finely chopped tomatoes, chopped celery, black pepper and salt.
Saute the ingredients with the wine. Strain the broth from the bones and fish heads, then bring it to a boil and add it to the vegetable mixture. Add the molluscs, finely chopped, sprinkle with fresh parsley and serve warm with garlic croutons.