In a medium bowl, whisk together soy sauce, brown sugar, sesame oil, minced garlic, grated ginger, crushed red pepper flakes, and black pepper until smooth.

Heat a large skillet over medium-high heat. Add ground beef, breaking it apart and cooking until browned, about 5-7 minutes.

Drain excess fat from skillet, leaving about 1 tablespoon in the pan.

Pour the sauce mixture over the cooked beef, stirring to coat evenly. Cook for another 2-3 minutes until the sauce thickens.

Serve the beef mixture over cooked rice, garnishing with green onions and sesame seeds.