Carefully separate the cabbage leaves and blanch them in boiling water for 1-2 minutes until slightly softened but still crisp. Drain and set aside.
Heat sesame oil in a large skillet over medium heat.
Add minced garlic and sauté for 1 minute until fragrant.
Add ground beef and cook, breaking it up with a spatula, until browned and cooked through, about 7-8 minutes.
Stir in soy sauce and red pepper flakes, cook for another 2 minutes to combine flavors.
Remove from heat and gently mix in sliced green onions, reserving some for garnish.
To serve, spoon the beef mixture into individual cabbage leaves formed as bowls.
Garnish with remaining green onions and sesame seeds.