In a large skillet over medium-high heat, brown the ground beef until fully cooked and no longer pink, breaking it into small crumbles with a spatula.
Drain any excess grease from the skillet.
Add the minced garlic and grated ginger to the beef and sauté for 1 minute until fragrant.
Whisk together the brown sugar, soy sauce, sesame oil, red pepper flakes, and black pepper in a small bowl.
Pour the sauce mixture over the beef and stir to coat evenly. Simmer for 2-3 minutes to allow the flavors to meld and the sauce to thicken slightly.
Divide the cooked rice into four bowls.
Spoon the beef mixture over the rice and garnish with sliced green onions and toasted sesame seeds.