In a large skillet over medium heat, add the ground beef. Cook until browned, breaking it apart with a spatula, about 5-7 minutes. Drain excess fat if necessary.
Add the diced onion and minced garlic to the skillet. Sauté for 3-4 minutes until the onion is translucent.
Stir in the shredded cabbage, soy sauce, brown sugar substitute, sesame oil, ground ginger, and black pepper. Mix well to combine.
Cook for an additional 5-7 minutes, stirring occasionally, until the cabbage is tender but still slightly crunchy.
Serve hot, garnished with sliced green onions and sesame seeds if desired.