In a large skillet over medium-high heat, cook the ground beef. It's okay to let it sit and brown really well before stirring it -- the brown will make more flavor!
When the beef is almost cooked through add the garlic. Cook until the ground beef is is no longer pink.
In a small bowl, whisk together the brown sugar, soy sauce, sesame oil, ground ginger, and red pepper flakes.
Add the sauce mixture to the ground beef, and cook for another minute.
Remove the skillet from the stove. Serve the beef over hot cooked rice with chopped green onion and sesame seeds as garnish.
This is a great dish to add some stir-fried vegetables to.