Prepare the rice using a rice cooker or stove as per instructions, ensuring it's ready to serve when the beef is done.
In a large saucepan, cook the ground beef over medium-high heat until browned and crumbled. Drain excess fat, if necessary.
In a mixing bowl, combine the soy sauce, brown sugar, sesame oil, garlic, ginger, and red pepper flakes. Mix until well-blended.
Pour the sauce mixture over the cooked beef and simmer for an additional 2-3 minutes, allowing flavors to meld.
Serve the beef over a bed of rice, garnished with green onions, sesame seeds, and optional vegetables like carrots and cucumbers.
Notes
For storage, keep the beef and rice in separate containers in the fridge for up to 3 days, or freeze the beef for up to a month. Reheat individual servings as needed.