In large pot, make roux of flour and oil, stirring until dark brown. Add vegs. until wilted. Cook okra in separate pot by frying in grease until almost all of rope is gone. Do not prepare ahead. Add shrimp to vegs., cook until brigh pink. Add tomatoes, cook about 5 minutes. Add cooked okra. Simmer for 5 min., add water, more or less depending upon consistency you prefer. Season with salt and pepper. Cook abt. 1.5 hrs. Add oysters 5 minutes before gumbo is done. Serve with rice.