Soak bamboo skewers in water for 30 mins.
In a small pot mix soy sauce, sugar ,sake and mirin, boil for 10 mins
Cut the chicken into cubes and the onion into long pieces.
Skewer chicken and onions altenately.
Heat oil in a flat frying pan.
Add the cooked skewered meat and salt, cook until browned on all side for 5 mins.
Dip chicken in store-bought Teriyaki sauce and serve.