North sea fish soup

This is a more interesting dish if you manage to assemble four or five different types of fish. The fishmonger should be able to provide the bones and trimmings for the stock. If not, then chicken stock, which is fuller flavoured, will substitute better than commercial fish stock. Bear in mind that denser-textured fish will take longer to cook than fragile specimens. So either cut fish like bass or hake slightly smaller or add them to the stock earlier. The idea is that all the fish should