Place sliced chicken in a bowl, add soy, oil and mirin and toss to coat, thread chicken onto skewers alternating with the spring onion.
For the glaze combine all ingredients in a sauce pan and heat through until thickened enough to lightly coat the back of a spoon, set aside.
Grill over a medium heat turning regularly until cooked through. Brush with the glaze all over and heat for a few seconds for glaze to caramelise. Sprinkle lightly with extra sansho pepper and either of the Gomasio blends then serve.