Brown the beef in a large skillet over medium-high heat, breaking it into crumbles. Cook for 5-7 minutes until no longer pink, then drain excess grease.
Add aromatics by returning the skillet to heat and adding minced garlic and grated ginger. Cook for 1 minute until fragrant.
Make the sauce by whisking together brown sugar, soy sauce, sesame oil, red pepper flakes, and black pepper in a small bowl.
Combine by pouring the sauce over the beef mixture. Stir well and simmer for 2-3 minutes until sauce thickens slightly.
Serve the beef over cooked rice and garnish with chopped green onions and sesame seeds.
