Heat oil in a large pot over high heat, add onions, celery and bell peppers, and saute 1 minute. Season with salt and 4 turns of pepper and saute 1 minute. Add the tomatoes, garlic, and shallots, and saute, stirring occasionally, about 4 minutes more.
Stir in stock, then add fish, Worcestershire, hot sauce, bay leaves, basil, oregano and thyme, and bring to a boil. Cook over high heat, stirring occasionally, about 8 minutes. Reduce heat to medium.
Stir in shrimp, okra and Creole seasoning, and simmer 10 minutes. Fold in oysters and crabmeat and simmer 5 minutes more. Skim the impurities from the top of the gumbo, turn the heat to high and boil vigorously 5 minutes. Slowly sprinkle in the file, stirring to incorporate thoroughly, and cook, stirring, 2 minutes more.
To serve, ladle gumbo into bowls or soup plates, add rice and sprinkle with green onions.
Yield: 12 first-course servings or 8 main-course servings