Heat a large nonstick skillet over medium heat.
Add the ground beef and cook until browned, breaking it up as it cooks.
Add the onion, garlic, and ginger.
Cook until the onion softens.
Stir in the sliced Chinese cabbage and cook for about 5 minutes, until it begins to soften.
Add the reduced-sodium soy sauce, sesame oil, red pepper flakes, black pepper, and grated carrots if using.
Stir well to combine.
Cook for 3 to 4 minutes, until the cabbage is tender but still crisp.
Remove from heat and garnish with sliced green onions.
Serve hot.
