Bring a saucepan of water to the boil. Add the snow peas and blanch for 1 minute. Drain, briefly refresh in cold water, and then drain again. Slice the snow peas lengthways and place in a mixing bowl.Add the mango and most of the mint, reserving some mint as a garnish. Set aside.
Whisk the dressing ingredients together in a bowl. Season to taste with sea salt and freshly ground black pepper and set aside.
Heat a wok over a medium heat. Add the vegetable oil and sauté the shallots and ginger for 3 minutes, or until caramelised.
Add the prawns and stir-fry for 2 minutes, or until just cooked. Stir in the lime juice to deglaze the pan, and then season with sea salt and freshly ground black pepper.
Add the prawn mixture to the mixing bowl. Pour the dressing over and toss until well combined.
Transfer to a serving platter, garnish with the remaining mint and serve.