Season the oxtail with soy sauce, Worcestershire sauce, allspice, thyme, salt and pepper. Marinate for 30 minutes.
Heat oil in a large heavy pot. Brown the oxtail pieces in batches over high heat until deeply browned on all sides. Remove.
In the same pot, sauté the onions for 5 minutes. Add the garlic and cook 1 minute.
Return the oxtail. Add the tomatoes, stock, brown sugar and Scotch bonnet (whole — it adds flavour without too much heat).
Bring to a boil, skim, then cover and simmer on very low heat for 2.5 hours until the meat is falling off the bone.
Add the butter beans and spring onions. Simmer uncovered for 20 minutes until the sauce is thick and glossy.
Remove the Scotch bonnet before serving. Serve with white rice or rice and peas.