Dry the chuck roast thoroughly and season generously with salt and black pepper all over.
Heat a small amount of sesame oil in a large skillet over medium-high heat and brown the beef on every side to seal in the juices.
Combine soy sauce, gochujang, sesame oil, minced garlic, grated ginger, honey, grated Korean pear, and rice vinegar in a bowl, mixing well until the sauce is uniform.
Place the seared beef into your slow cooker, Dutch oven, or a heavy pot.
Pour the prepared sauce evenly over the beef, coating it completely.
Arrange the carrots, potatoes, sliced onion, and if using, Korean radish around the meat.
If using a slow cooker, cook on low heat for 8 hours or on high heat for 4 to 5 hours until tender.
Alternatively, simmer gently on the stovetop over low heat, covered, for 3 to 4 hours, ensuring the pot does not dry out by checking occasionally.
Once cooked, transfer the roast to a serving platter and surround it with the cooked vegetables.
Spoon some of the cooking sauce on top for additional flavor.
Garnish with sliced green onions and a sprinkle of sesame seeds before serving.
