Remove and discard the tough outer skin from the lemongrass stalks. Roughly chop. Cut the chicken into strips and skewer.
Place the rest of the ingredients in a food processor or blender and pulse until smooth. Marinate the chicken in this paste for at least 1 hour.
Cook on the griddle.
To make the sambal: peel, de-seed and finely dice the papaya. Peel and chop the red onion. Place in a bowl, add the rest of the sambal ingredients and mix well.
Serve the chicken skewers with the sambal.
«Prepare the skewers in advance - griddle lightly but not so that the chicken is cooked through. Finish cooking just before you want to serve.»