In a medium bowl, combine the onion, garlic, soy sauce, brown sugar, sesame oil, rice vinegar, salt, and chili flakes. Add the short ribs to the bowl and mix well so they’re fully coated.

Cover and marinate in the fridge for at least four hours or overnight for best flavor.

Preheat your grill to medium heat (about 350 degrees Fahrenheit).

Grill the short ribs for three to four minutes per side, or until nicely charred and cooked through.

Top with sesame seeds and a drizzle of hot honey if desired. Serve hot.