In a large skillet, heat over medium-high heat and add the ground beef. Cook for about 5-7 minutes, breaking it apart with a spatula, until the meat is browned and no pink remains.

Add diced onions to the skillet with the browned beef. Sauté them for about 3-4 minutes until they become translucent and fragrant.

Stir in the minced garlic and ground ginger, cooking for another 1-2 minutes.

Introduce the shredded green cabbage to the skillet, mixing it with the beef and onion. Cook for 5-7 minutes until the cabbage becomes tender yet still has a slight crunch.

In a small bowl, whisk together the soy sauce, sesame oil, rice vinegar, and red pepper flakes, then pour over the beef and cabbage stir-fry.

Allow the dish to simmer for 2-3 minutes, enabling the flavors to come together. Adjust seasoning with salt and black pepper if desired. Garnish with green onions and toasted sesame seeds before serving.