1 vegetable oil in a small frypan. Add the puree and cook gently for 2 minutes. Add the spices and cook another 2 minutes. If needed, add a splash of water so the mixture resembles curry paste.
Pour mixture into a bowl and add all remaining ingredients except the chicken. Stir well and allow to cool to room temperature.
Make a few incisions in the chicken but don't cut to the bone. In a non-metallic bowl combine the chicken and marinade and turn to coat evenly. Cover with plastic wrap and marinate in the fridge 24 hours.
Heat BBQ and cook gently until cooked through and slightly charred, about 45 minutes.