In a mixing bowl combine green mango, herbs, chilli, fried shallots, fried garlic, prawns and 3 tablespoons of nuoc mam cham dipping fish sauce. Toss well, transfer to a plate or shallow bowl and garnish with crushed peanuts.
Combine the fish sauce, rice vinegar, sugar and 1/2 cup of water in a saucepan and place over medium heat. Stir well and cook until just before boiling point is reached, then remove from the heat and allow to cool. To serve, add the garlic and chilli, then stir in the lime juice. Store tightly sealed in a jar in the fridge, for up to 5 days.
Yield: about 1 cup