Beef bulgogi is a Korean dish made with thinly sliced marinated beef that is grilled or stir-fried. The marinade typically consists of soy sauce, sugar, sesame oil, garlic, and other seasonings, giving the beef a sweet and savory flavor. It is often served with rice and vegetables.
In a bowl, mix together soy sauce, brown sugar, sesame oil, garlic, ginger, green onions, sesame seeds, and black pepper to make the marinade.
Add the sliced beef to the marinade and mix well to coat. Cover and refrigerate for at least 1 hour, or overnight for best flavor.
Heat a large skillet or wok over medium-high heat and add vegetable oil.
Add the marinated beef (and any optional vegetables) to the skillet and cook, stirring frequently, until the beef is cooked through and caramelized, about 5-7 minutes.
Serve the beef bulgogi hot over steamed rice and garnish with extra sesame seeds and green onions if desired.