Cut the white part of the spring onion into 3cm pieces.
Cut chicken into bite-sized chunks and place in a bowl with the soy, mirin, sake, sugar, garlic and ginger. Stir well to coat the chicken and leave to marinate for 20 minutes (overnight is fine too).
Fold a piece of chicken in half and pierce with the skewer, push down towards the handle.
Next, pierce a piece of spring onion on the skewer.
Keep adding chicken and spring onion alternately until the skewer is full - should be about three pieces of meat.
Heat a frying pan on medium heat with a little oil. When the oil is hot, place the skewers in the pan and cook until both sides are brown, about 5 minutes on each side.
Then, add the sauce ingredients, cover with a pan lid and cook on a low heat for 2–3 minutes until the sauce thickens in the pan. Cook until the skewers are well coated.
Serve with Japanese Slaw.