2 pounds frozen Alaskan King crab legs (about 4 legs), rinsed and broken into large pieces at joints of necessary
5 quarts water
1 onion, halved
1 carrot, halved
1 teaspoon whole black peppercorns
1 bay leaf
2 fresh parsley sprigs
1 1/2 teaspoons salt
1/3 cup vegetable oil
1/2 cup bread flour
2 large onions, chopped
1 green bell pepper, chopped
2 celery ribs, chopped
1 1/2 pounds small shrimp, shelled
1/2 pound lump crab meat, picked over
2 dozen oysters, shucked, reserving their liquid
1 cup thinly sliced scallion greens (about 1 bunch)
Accompaniment: Cajun-style White Rice
Directions
In a 9 1/2-to 10-quart heavy kettle simmer stock ingredients, uncovered, 30 minutes. Transfer crab legs with tongs to a work surface and cool until they can be handles. Simmer stock 15 minutes more and pour through a large fine sieve into a large bowl. Return stock to kettle and keep warm, partially covered.
Cut open crab shells with shears and remove meat, discarding shells and cartilage. Cut king crab meat into bite-size pieces and transfer to a small bowl.
In a heavy skillet (preferably cast-iron) cook oil and flour over moderately low heat, stirring constantly with a flat-edged metal or wooden spatula, until roux od the dark reddish-brown color of chestnut shells, about 45 minutes. (Alternatively, make Microwave Brown Roux , and transfer to skillet.) Roux may be made 1 week ahead, cooled completely, and chilled, covered, in a glass or stainless-steel bowl. Reheat roux in skillet over moderately low heat, stirring, before proceeding. Add onions, bell pepper, and celery and cook, stirring occasionally, until vegetables are softened.
Add roux mixture by large spoonfuls to hot stock, stirring well after each addition, and bring to a boil, stirring. Simmer gumbo, stirring occasionally, 15 minutes. Add shrimp and simmer, stirring, 2 minutes. Stir in king crab meat, lump crab meat, and oysters with their reserved liquor and simmer, stirring occasionally, until edges of oysters begin to curl, about 2 minutes. Stir in scallions, cayenne, and salt to taste. Gumbo may be made 1 day ahead, cooled completely, uncovered, and chilled, covered.
Serve gumbo ladled over rice in large soup plates.
