In a bowl, mix the lime zest with all the other ingredients up to and including the salt, add the prawns, mix, cover and marinate for approx. 20 mins. Thread the prawns onto the skewers.
Grill the skewers over/on a high heat (approx. 250°C) for approx. 1 min. on each side.
Puree the avocado, water, coriander, chilli pepper and salt with the reserved lime juice.
Plate up the peach, cherry tomatoes and rocket, drizzle with the dressing, serve with the prawn skewers.