Very finely chopped onion fry in butter and a lid, ten minutes remove the lid, fry the onion until yellow, add the chopped tomatoes, parsley and garlic and stew for another 15 minutes. Place in a large saucepan well scrubbed mussels, pour 1 1/2 cups (300 ml) of water and boiled until the open (2-3 minutes). The mussels are removed from the shell, strain broth with mussels and added gradually puree of tomatoes and onions. Dusted with a lot of pepper and warmed. If the mixture is quite thin, add a little grated hard white bread without crust.