Thread the chicken, pineapple and onion alternately onto skewers.
Combine the soy sauce with all the other ingredients up to and including the peanut butter. Brush the skewers with half of the marinade, cover and marinate in the fridge for approx 1 hr.
Combine the remaining marinade with the coconut milk, chilli, peanut butter and reserved pineapple juice, simmer for approx. 5 mins.
Grill the skewers over/on a medium heat for approx. 15 mins. all over, sprinkle with fleur de sel and coriander. Serve with the dipping sauce.