Preheat the oven to 160°C, 140°C Fan, Gas Mark 2. Heat half the oil in a large non-stick frying pan. Place the joint on a chopping board and season with pepper all over. Brown the joint on all sides and transfer to a large ovenproof dish. Add the remaining oil and cook the onion and garlic for 2-3 minutes until soft.  Transfer to the casserole dish with the joint. Add the stock, soy sauce, barbecue sauce, honey, gochujang and pears.  Bring to the boil, cover and slow roast in the oven for 3-3½hours until the beef is tender. Transfer the beef to a clean chopping board and `pull’ the cooked beef apart by securing the joint with a fork and shredding the meat with another fork. Serve in Bao buns garnished with spring onions.