Ingredients

Makes about 8 cups, serving 4

　　1 pound medium shrimp, shelled, reserving shells

　　1 bay leaf

　　8 cups water

　　1 1/2 tablespoons vegetable oil

　　3 tablespoons all-purpose flour

　　1 cup chopped onion

　　1/2 cup chopped green bell pepper

　　1/2 cup chopped celery

　　1 pound frozen Alaska king crab legs, rinsed

　　1/2 cup long-grain white rice

　　1/2 cup drained canned whole tomatoes, chopped

　　1/4 cup thinly sliced scallion greens cayenne to taste

　　

Step 1

In a 4-quart saucepan simmer reserved shrimp shells, bay leaf, and water, partially covered, 15 minutes and strain through a sieve into a bowl. Return shrimp stock to pan and keep warm.

　　

Step 2

In a heavy skillet (preferably cast-iron) cook oil and flour over moderately low heat, stirring constantly with a flat-edged metal or wood spatula, until roux is a couple of shades darker than peanut butter, about 30 minutes. Stir in onion, bell pepper, and celery and cook, stirring occasionally, until vegetables are softened.

　　

Step 3

Stir roux into stock and bring to a boil, stirring. Add crab legs and simmer, partially covered, stirring occasionally, 15 minutes. Stir in rice and tomatoes and simmer, stirring occasionally, 12 minutes.

　　

Step 4

Transfer crab legs to a work surface. Cut shells open with kitchen shears and remove crab meat, discarding shells and cartilage. Tear crab meat into bite-size pieces and stir into gumbo. Add shrimp and simmer until just cooked through, about 3 minutes. Stir in scallion greens, cayenne, and salt and pepper to taste. Gumbo may be made 1 day ahead, cooled, uncovered, and chilled, covered.