Fish and Clam Soup

Impressive and delicious, this soup is a masterpiece of finesse and understanding about the nature of food. It requires a rich meat stock, a fish, shucked small cherrystone clams, and a head of celery cabbage. It involves three simple procedures: steaming the vegetable separately so that it retains its crisp texture and doesn’t dilute the stock; poaching the delicate fish in a rich stock; and merely scalding the clams, so that they are plump with juice and extremely