Combine the Marinade ingredients in a ziplock bag. Add the chicken and set aside to marinate for at least 3 hours, preferably overnight.

Remove the chicken from the Marinade, shaking off the excess. Keep the Marinade for the Sauce (below).

Brush the BBQ with oil and heat to medium high, or heat the oil in a skillet over medium high heat.

Cook the chicken for around 7 minutes on the first side and 5 minutes on the second side, or until cooked through.

Transfer the chicken to a plate, cover loosely with foil and rest for 5 minutes.

Serve with Sauce and garnished with fresh cilantro leaves, if using.

Pour the marinade into a small saucepan over medium heat.

Add the water and bring to a simmer. Cook for at least 10 minutes, or until thickened to desired consistency. (Note 1) Transfer to a sauce bowl.