Thai mango and prawn salad

Name: Thai mango and prawn salad
Ingredients: 500 gram medium king prawns, peeled, deveined, tails intact; 1 mango, peeled, seed removed, thinly sliced; 1 cucumber, seeded, thinly sliced; 1 bunch mint, leaves picked; 1 bunch coriander, leaves picked (retain roots); 1/2 red onion, thinly sliced; 2 clove garlic, crushed; coriander roots (retained from bunch), washed thoroughly; 2 long red chillies, roughly chopped; 8 cherry tomatoes, halved; juice of 2 limes; 1/4 cup palm sugar; 1/4 cup fish sauce