1 cup (240 ml / 8.1 oz) milk or water
1 teaspoon cocoa powder
1 teaspoon sugar
Heat the milk.
While heating the milk/water put the other ingredients in a mug and mix them very well. It's best if you try to grind it a bit using a spoon.
Fill half the mug with hot milk and stir very well.
Add the remaining milk to the mixture.