Drain the wings from the marinade and pat dry. Grill until crisp and golden, about 8 minutes per side. While the wings are grilling, melt the butter in a small saucepan on the grill. Whisk in the honey and mustard. Brush the glaze on the wings and allow to cook for another 2 minutes. Serve the wings mounded up on a platter sprinkled with green onions.