In a large skillet, cook ground beef, minced garlic, and finely chopped purple onion over medium heat for 6-8 minutes, or until the beef is no longer pink, breaking it up into crumbles.
2
In a separate small bowl, mix together brown sugar, soy sauce, sesame oil, crushed red pepper flakes, and black pepper to create the sauce.
3
Add the sauce to the cooked beef mixture in the skillet and stir well to ensure the beef is evenly coated. Cook for another 2-3 minutes to heat the sauce through.
4
Serve the Korean beef over hot cooked rice, and garnish with thinly sliced green onions and a sprinkle of sesame seeds.