1.To make avocado salsa, combine ingredients, except coriander leaves, in a medium bowl. Season to taste. Chill salsa until required. Serve garnished with coriander leaves
2.Cook oil, shallots, garlic, chilli, star anise and bay leaves in a small saucepan over low heat for 5 minutes or until oil begins to sizzle, cook a further 2 minutes for flavours to infuse. Remove from heat.
3.Shell and devein prawns, keeping tails intact. Thread each prawn onto a skewer starting at the tail end. Place skewers on an oven tray, season, then dot with butter.
4.Preheat grill (broiler), place prawns under grill for 1 minute or until just cooked through.
5.Remove and discard garlic from warm oil mixture. Place prawn skewers on a large platter, drizzle with warm oil mixture. Serve prawns with avocado salsa, scattered with coriander leaves.