Heat a large skillet over medium heat. Add the ground beef, breaking it apart with a spatula, and cook for about 4-5 minutes until it's browned and no longer pink.

Once the beef is browned, lower the heat and toss in diced onion and minced garlic. Sauté for 2-3 minutes until the onion is translucent.

Stir in the shredded cabbage, mixing it well with the beef and onion. Cook for an additional 5 minutes, stirring occasionally.

Pour in the soy sauce (or coconut aminos), sesame oil, rice vinegar, ground ginger, and red pepper flakes. Stir well and let it cook for another 2-3 minutes.

Remove the skillet from the heat and serve hot, garnished with sliced green onions and toasted sesame seeds.