In a large bowl, combine the oxtails with diced onion, grape tomatoes, diced scotch bonnet pepper, Caribbean green seasoning, salt, Worcestershire sauce, ketchup, black pepper, and Angostura bitters (if using). Mix well to coat the oxtails evenly. Cover and refrigerate for at least 2 hours, preferably overnight.
Preheat your oven to 350°F (180°C). In a heavy, oven-safe pot, heat the vegetable oil over high heat. Add the brown sugar and stir continuously with a dry spoon until it melts, becomes frothy, and turns an amber color.
Quickly add the marinated oxtails to the pot, including any marinade juices. Stir well to coat the oxtails in the caramelized sugar. Cover the pot and cook on medium heat for about 7 minutes.
Remove the lid and increase the heat to high. Cook until the liquid reduces and the oxtails are evenly browned. This process enhances the flavor and color of the dish. to 350 degrees F (180 degrees C).
Add the soaked navy beans (discard soaking water), chopped scallion, minced garlic, thyme sprigs, water, coconut milk, and allspice berries to the pot. Stir well and bring to a boil.
Cover the pot and place it in the preheated oven. Bake for approximately 3.5 hours, checking occasionally to ensure there is enough liquid. If necessary, add up to 1/2 cup of water or coconut milk to maintain the desired consistency.
Once the oxtails are tender and the beans are cooked, remove the pot from the oven. Discard the thyme sprigs and allspice berries. Skim off any excess oil from the surface. Garnish with chopped parsley and serve hot.
