In medium skillet (not cast iron), heat 3 tablespoons oil. Add okra, stirring frequently, and cook 20 to 30 minutes. (Fresh okra will take 30 minutes.) Add vinegar and cook another 10 minutes, until okra is no longer "ropy or slimy" and is lightly browned. Set aside.
In large pot, heat remaining 2 tablespoons of oil. Add flour, and cook over medium heat, stirring constantly, about 30 minutes, until roux turns dark brown and develops nutty aroma. Add onion, scallions, garlic, green pepper, celery and parsley, and cook 10 minutes or until vegetables are tender. Add tomatoes, okra, ham, fish stock, bay leaves, thyme, Worcestershire sauce, TABASCO® Sauce and salt. Simmer, uncovered, 45 minutes.
Add shrimp and crab meat, and simmer 5 to 10 minutes. Discard bay leaves and thyme. Serve gumbo over cooked rice with additional TABASCO® Sauce, if desired. Garnish with scallions and parsley.
Makes 6 servings.