01 - Pat the beef chuck roast thoroughly dry with paper towels. Lightly season all sides with salt and freshly ground black pepper.
02 - In a medium mixing bowl, whisk together soy sauce, beef broth, brown sugar, sesame oil, minced garlic, grated ginger, rice vinegar, and gochujang until the sugar dissolves completely.
03 - Arrange the sliced onions, carrots, and baby potatoes in an even layer at the bottom of a 6-quart or larger slow cooker.
04 - Place the seasoned beef roast on top of the vegetable bed. Pour the marinade mixture over the beef, ensuring the meat and vegetables are evenly coated.
05 - Cover the slow cooker with the lid. Cook on LOW setting for 8 hours until the beef is fork-tender and easily shreds apart.
06 - Carefully remove the beef roast and vegetables from the slow cooker. Transfer to a serving platter and cover loosely with foil to keep warm.
07 - Pour the cooking liquid from the slow cooker into a medium saucepan. Bring to a gentle simmer over medium heat.
08 - Whisk together cornstarch and water in a small bowl to create a smooth slurry. Gradually whisk the slurry into the simmering liquid. Cook for 2-3 minutes, stirring constantly, until the gravy thickens and coats the back of a spoon.
09 - Shred the beef using two forks or meat claws. Serve the beef alongside the tender vegetables, drizzled generously with the soy garlic gravy.
10 - Sprinkle the dish with sliced scallions and toasted sesame seeds just before serving for added texture and visual appeal.