Preparation

• Position a rack in the center of the oven and heat to 325°F. If you want neat slices, use butcher’s twine to snugly tie the roast every 2 inches or so down its length; otherwise, leave it untied. Season all over with salt and pepper.
• 在6 - 7-quart荷兰烤肉锅或其他深,重pot, heat the oil over medium-high heat. Add the roast and cook, adjusting the heat as necessary and flipping once about halfway through, until well browned on both sides, about 15 minutes total. Transfer the roast to a large plate and set aside. Discard all but about 2 Tbs. of the fat.
• Return the pot to medium heat. Add the onion and garlic, and cook, stirring often, until softened and golden, about 4 minutes. Stir in the carrots, celery, and 1 Tbs. of the ginger, and cook until they begin to soften, 2 to 3 minutes more (you are not going to cook them completely at this point).
• Add the vinegar and cook, stirring occasionally and scraping up any brown bits, until reduced by about half, 3 to 4 minutes.
• Stir in the broth, miso, remaining ginger, bay leaves, and 1 tsp. salt. Return the roast and any of its accumulated juices to the pot, nestling it into the liquid and vegetables. (If necessary, spoon some of the vegetables into a bowl temporarily to make room for the roast, and then spoon the vegetables back over the top.)
• Bring to a simmer. Cover the pot with a single layer of foil and then a heavy, tight-fitting lid. Transfer to the oven, and cook for 1-1/2 hours.
• Carefully uncover the pot and gently stir in the radishes, bok choy, and water chestnuts, flipping over the roast in the process. Re-cover with the foil and the lid, return to the oven, and continue cooking until both the meat and vegetables are very tender, about 1 hour more.
• Using tongs, carefully transfer the roast to a cutting board or large platter. Remove and discard twine, if using. To suit your needs, either slice the roast against the grain for serving, or use a fork to pull apart the meat into thick chunks, discarding any unwanted fat. Using a slotted spoon, arrange the vegetables around the roast and garnish with the scallions.
• Remove the bay leaves from the braising liquid. If you like, use a spoon to skim off as much fat as possible. Season the braising liquid with salt and pepper to taste. Spoon some of the braising liquid over the top of the meat and vegetables, serving the extra on the side.