Preheat the oven to 325°F (165°C).
Place the chuck or blade roast into a large Dutch oven or heavy oven-safe pot.
Add the grated apple, gochujang, diced onion, minced garlic, minced ginger, honey, apple cider vinegar, beef broth, soy sauce, and chopped kimchi (if using) directly into the pot with the beef.
Using a spoon or your hands, turn the beef in the sauce until it is well coated on all sides.
Cover the Dutch oven with a tight-fitting lid and place it in the oven. Cook for 4 hours, undisturbed, until the beef is very tender.
Remove the pot from the oven. Using two forks, shred the beef directly in the pot, mixing it back into the cooking liquid so it stays moist and flavorful.
Serve the shredded Korean braised beef in rice bowls, lettuce cups, or burritos.
