Oxtail Stew in Peanut Sauce (Kare-Kare)

Heat the oven to 375 degrees. Season the oxtails well with salt and pepper. Heat 3 tablespoons vegetable oil over medium to medium-high heat in a large Dutch oven or heavy-bottomed, ovenproof pot with a lid. Brown the oxtails on all sides then remove them to a plate. (You may need to do this in batches, so as not to crowd the pan.) Remove all but a tablespoon or so of the fat in the bottom of the pot and reduce the heat to medium. Add the onions, celery and carrot and cook them until they are soft and aromatic, about 3 to 6 minutes. Stir in the thyme sprigs, letting them just soften, then add the red wine and stir with a wooden spoon or spatula, scraping up any browned bits on the bottom of the pot. Add the oxtails to the pot with the shaoxing wine and enough stock to fully cover the meat. Cover the pot and let it cook in the oven for 2 1/2 to 3 hours, or until the meat is fork tender but not falling off the bone. About 15 minutes before the oxtails are done, prepare the vegetables: Heat 2 tablespoons oil in a medium nonstick skillet over medium heat. Add the eggplant, season with salt and pepper and cook, stirring occasionally, about 5 minutes. Add the garlic and cook another 5 minutes until eggplant is softened, then set it aside. Prepare the beans: Wipe the skillet clean, increase the heat to medium-high and add 1 tablespoon oil. Add the beans, season with salt and pepper and quickly stir-fry for 3 to 4 minutes, then set aside. Prepare the bok choy: Add the remaining oil to the pan, cook the bok choy with a pinch of salt until bright green and tender, about 2 minutes, then set aside. When the oxtails are tender, remove the meat from the liquid in the pot and set it aside on a plate. Strain the fat and any other matter out of the braising liquid and discard it. You should have 5 cups of liquid; if you have less, add additional stock to total 5 cups, then simmer the liquid over medium-high heat until it has reduced by half. Turn the heat to low, and using a hand blender, mix in the peanut butter and soy sauce and sugar, to taste. Add the achuete oil, blend again and let simmer for 2 minutes to thicken slightly. Return the meat to the pot and let it cook until heated through, a minute or two. Serve hot with the room temperature vegetables on top, rice and bagoong on the side.