Cut into the thick parts of the chicken and butterfly to even the thickness. Coat with shio-koji, put the chicken in a resealable plastic bag, then let it sit in the refrigerator overnight.

Remove from the refrigerator 30 minutes (1 hour in wintertime) before cooking. Microwave for 18-20 minutes. You could also grill it.

If using an oven, bake for 18-20 minutes at 200°C.

If pan frying, cook it on parchment paper or aluminum foil, since it burns easily. First fry the skin side down, cook it to a crisp, then turn over the chicken.