Preheat the oven to 325°F (160°C).

Sear the beef. Heat the oil in a 5-quart Dutch oven over medium heat. Pat the beef pieces dry, season them with salt and pepper, and sear them in batches for 4–5 minutes per side until browned. Transfer to a plate.

Make the braising liquid. Add sliced ginger, chopped scallions, and grated garlic to the pot and brown for about 2 minutes. In a large measuring cup, whisk together the soy sauce, beef stock, sake, brown sugar, and orange zest until combined. Pour into the pot.

Return the beef to the pot and bring to a gentle simmer. Cover and transfer to the oven to braise for 3 to 3.5 hours, checking for doneness at around 2.5 hours. If the liquid evaporates too quickly, add more beef stock.

While the beef braises, prepare the garnish. Combine the minced cilantro, additional scallions, and a touch of olive oil in a bowl. Season lightly with salt and pepper and set aside.

Once the beef is tender and easily shredded, remove the pot from the oven and let it rest for 15 minutes in the juices. Transfer the beef to a bowl, discard the ginger and scallion pieces, and skim off the fat.

Whisk together cornstarch and water, then bring the braising liquid to a simmer for 3-4 minutes to thicken. Toss shredded beef in the sauce before serving immediately over rice with the cilantro garnish.