Trim chicken and cut into 3cm cubes, soak skewers in water
Heat oil in a pan, add the onion and stir until soft. Transfer them to a food processor or blender. Add all the remaining ingredients to the blender (except chicken) and process for 1 minute or until smooth
Thread the chicken cubes onto skewers, place on a lightly oiled baking tray, brush with the peanut butter mixture from the blender.
Cook under a preheated grill for around 5 minutes on each side, brushing with the remaining peanut butter mixture as you go along. Cook until chicken is cooked through.
Place remaining peanut butter mixture in a small pan, stir over medium heat for 3 minutes until heated through.
Serve chicken skewers and pour over peanut butter sauce.