Melt the milk chocolate in a bowl over a pan of simmering water, gradually adding the milk. Allow to melt slowly while mixing gently. Put the preparation into the blender and mix for 20 seconds on speed 1. Pour the mixture into a glass.
Grind the mint leaves with the mini-grinder, using 6 pulses on speed 2. Arrange the mint on the preparation and mix. Serve cold or warm, as a dessert.