To make the stock, heat the butter or oil in a large pan, add the chopped vegetables, cover and cook slowly until soft and translucent. Drain the fish bones and add to the pan, cover and cook for a few minutes. Pour in the wine and cook uncovered until it has reduced by half. Add the cold water and bring to the boil. Add the herbs, mushroom trimmings and peppercorns and simmer gently for 20 minutes, skimming occasionally. Strain the stock through a fine strainer. Cover with clingfilm and cool quickly. To make the soup, bring the fish stock to the boil. Place the saffron in a bowl and pour on 2 tablespoons of the stock. Ladle a little stock into a small pan and season lightly in preparation for the cooking of the fish. Add the carrot and leek to the large pot of stock, simmer for 5 minutes. Poach the prawns in the small pan for 1 minute. Add the sole, poach for 1 minute. Add the scallops, poach for 1 minute. Remove fish with a slotted spoon and add to the soup with the saffron and its liquid. Heat, season and add the herbs. Serve in warm soup bowls. NB: the stock may be kept in the refrigerator for up to 3 days, or if not using straight away it may be frozen. DISCLAIMER(c) Copyright 1996 - SelecTV Cable Limited. All rights reserved. Carlton Food Network http://www.cfn.co.uk/