Skin the fish and cut it into convenient pieces. Place 450g (1 lb) in a largish saucepan. Pour 1.4 litres (2 1/2 pints) of cold water over the fish and add the parsley stalks, onions, wine and some salt.

Bring gently to the boil and simmer very slowly for 30 minutes. Strain the soup into a bowl, retrieve all the flesh from the fish and put on one side. Discard the remainder.

In a separate pan, melt the butter, stir in the flour and let it cook gently for 2 minutes without browning. To this roux add the strained fish stock little by little. Let it simmer for 10 minutes, then add the best pieces of fish. Adjust the seasoning and put the soup aside while you make the fishballs.

Pur�e the reserved raw fish, together with all the other fishball ingredients in a liquidiser until you have a fine paste. Form into little balls the size of marbles with lightly floured hands. All this can be done well in advance.

When the time comes to serve, all that remains to be done is to bring the soup to the boil, drop in the fishballs and let them poach for 6 minutes in the simmering soup. If they do not rise after a minute or two, free them gently from the bottom of the pan with a wooden spoon. Just before serving stir in the cream and heat through.

For the white fish you can use haddock, coley, angler, hake.