Cut the chicken thighs into large bite-size pieces. Sprinkle salt and sake over them, mix well, and let them sit for a few minutes.
Thinly slice the onion. Mix all the ingredients for the ginger sauce. Prepare the shredded cabbage and any other side vegetables you desire.
Just before cooking the chicken pieces, coat them with potato starch. Heat oil in a frying pan over medium heat. Start cooking the chicken until nicely browned. Add the sliced onion and cook for a couple of minutes or until the onion is softened. Then add the ginger sauce. Stir and cook for a couple of minutes. When the sauce is starting to slightly thicken, remove from heat and serve.