Preheat the oven to 325°F (165°C).

Sear the beef chuck roast in vegetable oil for 4-5 minutes on each side until a golden-brown crust forms. Remove and set aside.

Sauté sliced onions and minced garlic in the residual oil for 3-4 minutes until soft and fragrant.

Pour in beef broth, soy sauce, brown sugar, rice vinegar, gochujang, sesame oil, and ground ginger. Simmer for 2 minutes.

Return the seared beef to the pot, mostly submerging it in the broth. Cover the pot.

Add carrots, quartered potatoes, and sliced shiitake mushrooms around the roast.

Transfer the covered pot to the oven and roast for 3-4 hours until the beef is fork-tender.

Remove the roast and transfer to a platter, arranging cooked vegetables around it.

Skim excess fat off the sauce and drizzle it over the beef and vegetables.

Garnish with chopped green onions and sesame seeds before serving.