A fine kettle of fish: seafood soup

Bisque: This low-fat crab dish is flavored with chopped celery and onion and dry sherry

There's some strategy to making good seafood soup: Use good-quality fish or shellfish, add the ingredients in stages, and don't overcook.

Fresh fish and shellfish should be mild-smelling, with no fishy odor or trace of ammonia, and the flesh should feel firm. If you buy previously frozen seafood, be sure it hasn't been defrosted longer than two days.

Because a soup made with fish or seafood combines ingredients with varying cooking times, you'll need to add the different items in stages. Potatoes, onions and other sturdy, aromatic vegetables go into the kettle at the beginning, whereas any green vegetables and the fish or shellfish generally get added toward the end of the cooking. It's a rare seafood soup or stew that needs more than half an hour's simmering after you've added the fish or shellfish. The reason? The delicate proteins in fish and shellfish don't stand up well to prolonged cooking.

Most bisques are rich with butter and cream, but not this delicious low-fat version.

Fresh Crab Bisque

Serves 6

2 teaspoons butter

2 cups coarsely chopped onion

1/3 cup chopped celery (including leaves)

2 large russet potatoes, peeled and cubed

2 cups fish stock

2 tablespoons tomato paste

2/3 cup dry sherry

2 cups nonfat milk

1/2 pound cooked fresh crab meat

Salt and pepper, to taste

Parsley or tarragon sprigs, for garnish

In stockpot, heat butter; saute onion and celery over medium-high heat until soft but not browned. Add potato and fish stock. Bring to a boil. Lower heat, cover and simmer until potato is soft (about 20 minutes). Add tomato paste, sherry and milk. Cook 10 more minutes.

Puree mixture in blender. Return to stockpot; add crab meat. Heat through. Season to taste. Serve in warmed bowls, garnished with herb sprigs.