Prep the Beef: Start by thinly slicing your beef against the grain. This will help the meat stay tender and cook evenly. If the beef is a bit tough, you can freeze it for 15–20 minutes before slicing to make it easier to cut.

Make the Marinade: In a bowl, combine the soy sauce, sesame oil, garlic, ginger, gochujang, and brown sugar. Stir everything together until the sugar is dissolved and the ingredients are well-mixed. This marinade will give your beef that savory, slightly sweet, and spicy flavor.

Marinate the Beef: Place your sliced beef in the marinade, making sure it’s fully coated. Let it sit for at least 15 minutes to allow the flavors to soak in. If you have more time, marinating it for 30 minutes or even overnight will intensify the flavor.

Cook the Beef: Heat a large skillet or wok over medium-high heat. Add a splash of sesame oil for extra flavor. Once hot, add the marinated beef in a single layer. Cook for 3–4 minutes on each side or until the beef is browned and cooked through. Avoid overcrowding the pan—if you’re making a larger batch, cook the beef in batches to ensure it gets a nice sear.

Finish the Dish: Once the beef is cooked, sprinkle it with chopped green onions and sesame seeds for added texture and freshness.

Serve and Enjoy: Serve your Korean beef with a side of steamed rice, sautéed vegetables, or a simple cucumber salad to balance out the richness. The tender beef and flavorful sauce will shine with every bite.