In a small mixing bowl, combine the sesame oil, tamari or soy sauce, water, rice vinegar, brown sugar (or chosen alternative), ground black pepper, and sesame seeds if using. Stir vigorously to combine and set aside.
Warm a large sauté pan or skillet over medium-high heat. Add the oil of choice, then immediately add the chopped garlic, minced ginger, and ground beef. Cook the mixture while stirring and breaking apart the meat until it is fully browned, approximately 5–7 minutes.
Once the beef is cooked through, incorporate the shredded cabbage and carrot matchsticks into the pan. Stir and cook for about 5 minutes, allowing the vegetables to soften but retain a slight crunch.
Pour the pre-mixed sauce into the skillet, tossing the ingredients well to evenly coat everything. Add the sliced scallions and raise the heat slightly. Continue cooking for an additional 3–4 minutes until the sauce has thickened slightly and is absorbed into the mixture.
Remove from heat and serve immediately. Enjoy alone, or serve over steamed rice, noodles, cauliflower rice, or spiralized zucchini for a lower-carb alternative.