Place the beef in the base of your slow cooker. If the pieces are large, cut them to fit in a single layer.
Mix together the ginger, gochujang, garlic, soy sauce, rice vinegar, sesame oil, brown sugar and beef stock until well combined. Pour over the beef. Add the star anise if using.
Cook on low for 4 hours, or until the meat shreds easily when pulled with two forks. Cooking times vary between slow cookers so use the shred test rather than the clock.
Remove the star anise. Shred the meat directly in the slow cooker using two forks, then toss it through the sauce until every strand is coated.
Serve over rice with sliced spring onions, steamed bok choy, cucumber salad, carrot salad and kimchi alongside.