For the Skewers:
Combine marinade ingredients in a bowl. Set aside 1/4 c. for later use.
Marinate chicken 2-3 hours or overnight.
Skewer chicken, bring marinade to a boil on the stovetop. While that's happening, grill the chicken, basting with reserved marinade.
When done, drizzle with boiled marinade and garnish with scallions.