
Clean the oxtail by placing them in a bowl and adding the vinegar. Toss to coat, then rinse with water. Drain and set aside in a bowl.
Season the oxtail with the achiote oil, adobo, sazon, oregano, black pepper, garlic powder, sofrito, garlic and liquid sazon seasoning. Toss the oxtail to coat the pieces with the marinade mixture. Cover with plastic wrap and marinate for one hour, or up to overnight.
In a large Dutch oven, add 2 tsp of achiote oil and heat to medium heat. Remove the oxtail from the marinade (save it!) and brown the pieces for 3-4 minutes per side.
Pour the marinade into the pot on top of the oxtail, then add the wine, chicken bouillion and tomato sauce. Stir the mixture and scrape the bottom of the pan to remove any brown bits.
Add the peppers, onion, thyme and bay leaves into the pot. Add enough water to completely cover the oxtails. Bring the mixture to a boil, then reduce to medium low and cover, leaving the edge of the pan slightly uncovered so that the mixture can reduce.
Cook the oxtail stew for 3 hours, until they're tender and ready to fall off the bone. Season with salt to taste, then serve hot.