Remove the skin and cut the juicy flesh off the mangoes. Place the fruit in a blender or food processor, along with any juice left on the chopping board. Add the milk, lime juice and zest, ice and mint leaves and give it all a good whiz until smooth. Taste, and add a little honey if needed, then give it another quick whiz. Chill in the fridge before serving, then garnish with a few mint leaves.