Rinse the chicken leg and use a fork to prick the skin in several places.
Combine sake, lemon juice, ginger and a pinch of salt in a shallow dish. Add the chicken and marinate for at least 2 hours.
Transfer the chicken to a plate and place the chicken in a steamer over the boiling water. Cover and steam the chicken for 20 minutes, or until cooked.
Mix well the dipping sauce and set aside.
Cut the chicken into bite sized pieces, and serve with dipping sauce.