To make sauce, combine all ingredients in a jug. Season. Mix well.
Cut the cheeks from the mangoes. Using a large spoon remove the mango fruit from the cheeks and cut into 2cm cubes.
To serve, arrange lettuce on a serving platter. Top with prawns, avocado and mango. Drizzle with dressing. Top with micro herbs. Serve with crusty bread.
TipDressing can be made up to three days ahead. Store in a sealed jar in the fridge. Delicious with on tacos, sandwiches or as a dipping sauce for seafood.