Remove outer cabbage leaves. Cut into quarters. Remove core.
Slice cabbage into thin shreds.
Mince garlic and ginger.
Heat vegetable oil in wok or skillet over high heat.
Add garlic and ginger. Stir-fry 30 seconds until fragrant.
Add cabbage. Toss to coat with oil.
Stir-fry 3 to 4 minutes, tossing frequently, until tender-crisp.
Add soy sauce, rice vinegar, sesame oil, sugar, and red pepper flakes.
Toss together. Cook 1 more minute until sauce coats cabbage.
Taste. Add salt and pepper if needed.
Remove from heat. Transfer to serving dish.
Garnish with sesame seeds, green onions, and cilantro.
Serve hot as side or over rice as main.