Cook the rice according to package instructions until soft and fluffy. Fluff with a fork and keep warm.
Heat a large pan over medium heat. Add the ground beef and cook for 5 to 7 minutes, breaking it into small pieces until fully browned. Drain excess fat if needed.
Add the minced garlic to the beef. Stir and cook for 1 minute until fragrant, making sure it does not burn.
Pour in the brown sugar, soy sauce, sesame oil, ground ginger, and red pepper flakes. Stir well until the sugar dissolves and the beef is evenly coated.
Let the mixture simmer for 3 to 5 minutes, stirring occasionally, until the sauce thickens and sticks to the beef.
Spoon cooked rice into serving bowls, spreading it evenly.
Add the beef mixture on top of the rice. Spoon extra sauce over the top if desired.
Garnish with sliced green onions and serve warm.