Slice the beef thinly.
Make the marinade with soy sauce, sugar, garlic, sesame oil, and pepper.
Mix the beef with the marinade, along with onion, carrot, and green onion, and let it marinate for at least 30 minutes.
Heat oil in a pan and stir-fry the marinated beef and vegetables.
When cooked, plate the dish and sprinkle with sesame seeds.