Cook the Beef: Heat a large skillet over medium heat. Add the ground beef and cook until browned and crumbly, about 5–7 minutes. Drain excess grease if necessary.
Add Aromatics: Stir in the minced garlic and grated ginger. Cook for 1–2 minutes until fragrant.
Make the Sauce: In a small bowl, whisk together soy sauce, brown sugar, sesame oil, rice vinegar, and red pepper flakes.
Combine and Simmer: Pour the sauce over the beef and stir to coat evenly. Let simmer for 3–5 minutes until slightly thickened.
Finish and Serve: Stir in green onions and sesame seeds. Serve over rice and garnish with a fried egg, kimchi, or steamed veggies if desired.