Combine the lemon zest, tamari or soy sauce, oil and garlic in a bowl, add the chicken and marinate, covered, overnight in the refrigerator. Put 6–8 bamboo skewers in water to soak overnight. For the lemon sauce, combine all the ingredients except the cornflour in a small saucepan, place over a gentle heat and bring to a simmer. Combine the cornflour and 2 tablespoons of water in a small bowl, stir into the sauce and continue stirring until thickened. Cook for a few more minutes, then set aside. Thread the strips of chicken onto soaked bamboo skewers. Don’t overcrowd the skewers, but thread the chicken all along their length to prevent the skewers from burning. Grill or barbecue and serve with the lemon sauce, lemon halves and coriander.