Oxtails need the gentle, slow heat of a braise to soften their connective tissue. The result is a dish with a rich beef flavor and a velvety sauce. Oxtails are usually sold in 1- to 3-inch cross sections; because of the amount of bone, you should buy at least 1 pound per person. Pieces from the very narrow tip of the tail yield almost no meat and are best saved for the stockpot.
Preheat the oven to 300°F.
Heat in a Dutch oven or large ovenproof skillet:
Whisk together in a large bowl:
Dredge:
in the seasoned flour. Brown the oxtails in batches, transferring them to a plate as they finish. Pour off the fat and add to the pan:
Scrape up any browned bits and let the wine cook off a bit. Add:
Return the oxtails to the pan and bring to a boil over high heat. Cover, transfer the pan to the oven, and cook until the oxtails are very tender, 4 to 5 hours, adding more stock if needed. During the last 45 minutes of cooking, add:
Transfer the oxtails and vegetables to a platter with a slotted spoon and skim off as much fat as possible (a gravy separator comes in handy here). Reduce the liquid over medium-high heat until it thickens somewhat, or add:
Season to taste with:
Pour the sauce over the oxtails and serve with: