1. Heat oil in a large Dutch oven or heavy-bottomed pot over medium heat. In a large bowl, season the oxtails with the fish seasoning, seasoning salt, black pepper, allspice, and salt. Rub meat with seasoning. Cook oxtails in batches, allow to brown completely on each side before turning, about 4 minutes per side. Transfer cooked oxtails to a plate. Continue cooking remaining oxtails.
2. Cook onion, scallion, garlic, and scotch bonnet until softened, stirring often to prevent burning, about 5 minutes. Stir in tomatoes and cook until mixture thickens slightly, about 5 more minutes. Using a wooden spoon, stir in tomato paste; cook for 3 minutes, stirring often. Add worcestershire sauce, and browning sauce; stir. Return oxtail and all its juices to pot. Add thyme. Pour chicken stock plus 2 cups water over oxtails to cover; stir. Bring to a boil over medium-high heat. Cover and reduce to simmer on low heat for 30 minutes. Stir in butter beans, cover pot and simmer for another 30 minutes. Remove lid and simmer for another 15 to 20 minutes until meat is tender and sauce thickens. Adjust consistency of stew by adding more or less water, if necessary. Adjust seasoning to taste with salt and pepper, if needed.
3. Serve oxtail with rice and peas or white rice. Garnish with chopped scallion.