Heat a large skillet over medium heat. Add the ground beef and cook until browned, about 5-7 minutes. Drain any excess fat.
In a small bowl, whisk together soy sauce, brown sugar, garlic, sesame oil, ginger, and red pepper flakes. Pour over the ground beef and let simmer for another 2-3 minutes.
Serve the beef mixture over cooked rice. Garnish with green onions and sesame seeds.