Brown the Beef: Heat a large skillet over medium heat. Add the ground beef, breaking it up with a spoon, and cook for 5-7 minutes until browned. Drain excess fat if needed.
Add the Aromatics: Stir in the minced garlic and ginger, cooking for 1 minute until fragrant.
Season the Beef: Add soy sauce, sesame oil, brown sugar, and red pepper flakes (if using). Stir well and let the mixture simmer for 2-3 minutes to absorb flavors.
Finish & Serve: Stir in chopped green onions, season with salt and pepper to taste, and serve over steamed rice. Garnish with sesame seeds if desired.