Cut the wings into three pieces through the joints. Discard the wing tips, or save for chicken stock.
Transfer the remaining chicken drumettes and flats to a large resealable plastic bag or a bowl.
For the Marinade: In a small saucepan, combine the soy sauce, 1/4 cup water, brown sugar, vinegar, scallions, garlic, sesame oil and ginger. Bring to a boil, then reduce the heat and simmer for 10 minutes.
Cool completely, then pour over the chicken wings.
Seal the bag and refrigerate for several hours, or overnight.
Drain the wings, discarding the marinade.
When ready to cook, set Traeger temperature to 350℉ and preheat, lid closed for 15 minutes.
Cook for 45 to 50 minutes, or until the skin is brown and crisp and the meat is no longer pink at the bone. Turn once during the cooking time to prevent the wings from sticking to the grill grate.
Remove from grill. Sprinkle with sesame seeds to serve. Enjoy!