The chocolate you use is really important, choose one that you would enjoy eating and is at least 70% cocoa solids. I'm not a huge dark chocolate fan and use it much more for baking than eating or indeed drinking, I did however really really enjoy this hot chocolate and will definitely make it again.
Bring the milk, water and sugar just to the boil in a medium saucepan. Remove the pan from the heat and whisk in the chocolate. At this point the hot chocolate needs to be blended. At Laduree this is done with a hand-held blender, if you have one leave the hot chocolate in the saucepan whip it with the hand-held blender of one minute. If you do not have a hand-held blender transfer the hot chocolate to a traditional blender and whip on high speed for one minute. The chocolate should be served immediately, while still hot and frothy.
If you want to store the hot chocolate leave it to cool before putting it in the fridge, tightly covered, for up to two days. Re-heat and re-whip before serving.