Place fish in a glass dish and pour over lime juice. Cover and refrigerate for 1 hour. Add chilli, onion, tomato, coriander and avocado. Place a pastry cutter in the centre of a plate, fill with the mixture, packing down well (or divide between serving dishes). Remove pastry cutter, drizzle sweet chilli sauce and coconut cream around. Top with extra coriander and serve with a lime wedge.