Preheat an oven to 325 F.
Sear the beef. Heat the oil in a 5-quart Dutch oven over medium heat. Pat the beef pieces dry with a paper towel and season liberally all over with salt and pepper. Arrange the beef pieces in a single layer and sear the beef for 4-5 minutes per side until it’s deeply browned. You may need to do this in batches. Transfer the beef to a plate. Discard all but 1 tablespoon of fat.
Make the braising liquid. Add the sliced ginger, scallions, and garlic to the pot and let them brown in the oil for 2 minutes. Meanwhile, whisk together the soy sauce, beef stock, miso, brown sugar, sake, and orange zest together in a large measuring cup until the sugar has dissolved. Pour the braising liquid into the pot and bring to a gentle simmer, using a wooden spoon to scrape up any browned bits from the bottom of the pot.
Braise. Return the beef to the pot and bring to a gentle simmer. Cover, and transfer to the oven to braise for 3 - 3 1/2 hours (start checking for doneness at 2 1/2 hours). If the liquid is evaporating too quickly, simply add a bit more beef stock to the pot.
Make the salsa verde. While the beef braises, combine the cilantro, scallion, shallot, serrano, garlic, oil, and orange juice together and season with salt and pepper. The sauce gets better as it sits, so I like to make it about an hour before we eat.
Finish the beef. Once the beef is tender and easily shredded with a fork, remove the pot from the oven and let the beef rest in the juices for 15 minutes. Then, transfer the beef to a large bowl. Discard the ginger, garlic, and scallion pieces, and skim off as much of the fat on the surface as possible. Whisk in the cornstarch and water slurry and bring to a simmer for 3-4 minutes. Toss the beef in the sauce once more and then serve right away over rice with the herby sauce on top.