Cut off the stems of shiso leaves and slice them thinly. Cut potatoes into bite-sized pieces and soak them in water to remove excess starch, then drain.

Slice chicken breast thinly using a diagonal cutting technique. Place chicken in a bowl, add 1 tbsp liquid shio koji, and massage. Let it marinate for 20 minutes.

Mix all the seasoning ingredients (☆) in a bowl.

Place the potatoes in a microwave-safe container, cover loosely with plastic wrap, and microwave at 600W for 3–4 minutes.

Heat salad oil in a frying pan over medium-low heat. Add the marinated chicken and cook until lightly browned. Flip the chicken, add the potatoes, and stir-fry for 1–2 minutes.

Add the mixed seasoning (☆) and stir-fry until the liquid is absorbed and the dish is well coated.