Make 3–4 slashes in each chicken drumstick with a sharp knife and place in a glass or ceramic bowl.
Mix together all the marinade ingredients in a small bowl and then pour over the chicken. Toss to coat evenly, cover and leave to marinate in the refrigerator for 6–8 hours, or overnight if time permits, turning the chicken occasionally.
Tip the chicken and marinade into a nonstick roasting tin and arrange the chicken in an even layer. Roast in a preheated oven, 200°C (400°F), Gas Mark 6, turning occasionally and basting with the marinade and juices, for 45–50 minutes, or until sticky and golden and cooked through – the juices should run clear when the thickest part of the meat is pierced with a knife.
Serve the chicken warm or at room temperature on a bed of lettuce leaves with steamed rice.