Put the oxtails in a large baking dish and sprinkle with salt, pepper and the Shaoxing wine. Marinate in the refrigerator overnight.
Preheat the oven to 375 degrees F.
Remove the oxtails from the marinade and pat dry. Heat a large cast-iron Dutch oven over high heat, and then sear the oxtails until brown. Remove the oxtails from the pan and set aside. Throw off some of the fat, but keep enough to saute the celery, carrots and onions until brown. Deglaze the pot with 1/2 cup of the wine and cook until the liquid is reduced down.
Return the oxtails to the pot along with the stock and remaining wine. Braise in the oven until the meat is almost falling off the bone, about 3 hours. Remove the oxtails and shred the meat, reserving the braising liquid.
For the kare-kare sauce, strain the reserved braising liquid and cook over medium heat in a saucepan to reduce until thick, skimming off excess fat. Stir in the soy sauce, peanut butter and sugar, and then blend until smooth using an immersion blender. Stir in the achuete oil until the desired color is achieved.
To serve, divide equal portions of the oxtail meat and a scoop of white rice onto plates and cover with the kare-kare sauce.
*Achuete oil is a Filipino oil made from infusing oil with achuete seeds. It is used primarily as a reddish-orange food coloring but also imparts a subtle flavor. It is an identifying element of the traditional kare-kare dish.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.