Preheat oven to 350 F.

To make the teriaky sauce, mix together ginger, mirin, sesame seeds, tamari, maple syrup, champagne vinegar, toasted sesame oil, and massage the chicken drummettes with the liquid mixture.

Transfer to a shallow glass dish and bake for 25 minutes covered. Remove cover and drain half of the liquid in the dish. Bake again, uncovered, for an additional 20 minutes or until tops of chicken are browned. Garnish with chopped green onion.