1/2 cup sake
1/2 cup soy sauce
1 tbsp sugar
1 garlic clove, crushed
1 piece fresh ginger root, grated
1/2 kg chicken breast, cubed
3 leeks, cut into small pieces (optional)
In a bowl, mix together sake, soy sauce, sugar, ginger and garlic. Put chicken into marinade and leave for at least 15 minutes - do not leave to marinate for an extended period of time.
Pre-heat grill. Grease 6 metal skewers and thread with chicken (alternating with leeks if using). Place on a baking sheet and brush with remaining marinade.
Grill for 5 minutes, baste again and grill for a further 5, or until chicken is cooked through.