* small raw shrimp, peeled and deveined; cooked crab meat; small shucked oysters Place the carcass in a stock pot, breaking it up, if necessary, to make it fit. Add water to cover. Bring to a boil, reduce to a simmer, and skim off any foam that comes to the surface. Add the sliced onion, celery, parsley, thyme sprig and bay leaf; simmer, uncovered, skimming occasionally, for 2 to 4 hours. (The longer you cook it, the richer the stock will be.) Do not let the stock boil or it will turn cloudy. Heat the oil in a large, heavy skillet (preferably cast iron), over medium heat. Stir in the flour and cook, stirring and scraping the entire bottom of the pan at least every 10 seconds, until the resulting roux cooks to a deep mahogany color, 10 to 15 minutes. Adjust the heat to prevent scorching, which can give a bitter taste. Turn off the heat and continue stirring a minute or two until the mixture no longer gets darker on the bottom. Carefully stir in the diced vegetables tables; dont let the roux splatter it can cause nasty burns. Stir to coat the vegetables evenly with roux; stir in the chile powder, salt, pepper, herbs and cayenne; set aside. (The roux may be prepared to this point while the stock cooks.) Strain the stock, let it stand until the fat rises to the top, and skim off the fat. Bring 8 cups of the stock to a boil in a large pot, stir in the roux vegetable mixture and simmer until slightly thickened, about 15 minutes. Add the shrimp, crab and/or oysters and simmer just until done, about 5 minutes. Taste for seasoning and correct if necessary. Serve in soup bowls over small scoops of rice. Serves 6 to 8. PER SERVING: 255 calories 22 g protein, 21 g carbohydrate, 9 g fat (1 g saturated), 92 mg cholesterol, 343 mg sodium, 1 g fiber. Jay Harlow, San Francisco Chronicle, 11/23/92. Posted by Stephen Ceideberg; December 2 1992. File ftp://ftp.idiscover.co.uk/pub/food/mealmaster/recipes/cberg2.zip