Begin by cutting the boneless beef chuck into 1-inch cubes. Ensuring even sizes helps with consistent cooking. Feel free to trim excess fat, but a little marbling is good as it enhances flavor during the slow cooking process.

In a large bowl, combine the soy sauce, beef stock, brown sugar, sesame oil, white pepper, ginger, garlic, onion powder, hoisin sauce, rice vinegar, and Sriracha. Stir until the sugar dissolves completely. This sauce will create that signature Korean flavor profile.

Transfer your beef cubes into the slow cooker and pour the sauce over them, making sure every piece is coated. This makes it super flavorful.

Cover the slow cooker and set it to cook on low for 7-8 hours or on high for 4-5 hours. During this time, the beef becomes tender, soaking up all the deliciousness of the sauce.

Once the cooking time is up, mix 2 tablespoons of cornstarch with two tablespoons of water to make a slurry. Add this to the slow cooker and stir gently. Cook for an additional 30 minutes on high to thicken the sauce.

When ready to serve, top with sliced green onions and a sprinkle of sesame seeds for that extra flair. This dish is best when paired with rice and those crunchy pickled veggies I mentioned earlier.