In a medium bowl, combine the soy sauce, sugar, sesame oil, garlic, ginger, and gochujang. Add the beef and mix to combine. Cover and refrigerate for at least 30 minutes or overnight.
Heat a large skillet over medium-high heat. Add the beef and marinade and cook until the beef is browned and cooked through, about 5-7 minutes.
Add the onions, carrots, mushrooms, bell peppers, and green onions and cook for an additional 5 minutes, stirring occasionally.
Serve the beef bulgogi over steamed rice.
Interesting Facts
Bulgogi is one of the most popular dishes in Korean cuisine.
The word bulgogi literally means "fire meat" in Korean.
Bulgogi can be made with beef, pork, or chicken.
Gochujang is a spicy, fermented chili paste that is a staple in Korean cooking.