In a heavy ungreased 12-inch skillet, fry the sausage over low heat, turning the slices frequently with a slotted spatula until the bottom of the pan is filmed with fat. Increase the heat to moderate and, turning the slices occasionally, continue to fry until the sausage is richly browned. Transfer the sausage slices to paper towels to drain. There should be about 1/2 cup of fat in the skillet; if not add oil to make up that amount.

Pat the pieces of poultry completely dry with paper towels and remove any large pieces of fat. Season the birds with 2 tsps of the salt and a few grindins of black pepper. Roll the meat in the flour to coat the pieces on all sides and vigorously shake off the excess flour.

Brown the poultry pieces, 5 or 6 at a time, in the hot fat remaining in the skillet. Turn the pieces frequently with tongs and regulate the heat so that they color deeply and evenly without burning. As they brown transfer the pieces to paper towels to drain.

Warm the roux over low heat in a heavy 12 qt enameled or cast-iron pot. When the roux is smooth and fluid, stir in the onions, scallions and celery. Stirring frequently, cook over moderate heat for about 5 minutes, or until the vegetables are soft. Mix in the green peppers. Then stirring constantly, pour in the warm water in a slow, thin stream and bring to a bo il over high heat.

Add the sausage slices, the pieces of poultry, the remaining 2 tsp of salt, the Tabasco and the red pepper. When the mixture returns to a boil reduce the heat to low and cover the pot partially. Simmer the gumbo for 2 hours. Remove the pot from the heat and, with a large spoon, skim as much fat from the surface as possible. Stir in the parsley and 2 tsp of the file' powder, and taste for seasoning. The gumbo should be hotly spiced and may require more Tabasco and/or red pepper.

Ladle the gumbo into a heated tureen and serve at once, accompanied by the rice in a seperate bowl. Traditionally, a cupful of the rice is mounded in a heated soup plate and the gumbo spooned around it.