Cook the noodles according to the instructions on the packet. Meanwhile, combine the peanut butter, lime juice, rice wine vinegar, honey and soy. Gradually whisk in 100ml warm water until you have a loose, runny consistency.
Drain the noodles and rinse in cold water. Add to a large bowl along with the cooked prawns, all of the chopped vegetables and the chopped mint. Drizzle over the peanut butter dressing and toss until coated. Divide between serving bowls and garnish with the remaining mint leaves.