Get some good cocoa (you deserve it)
European brands are usually good.
Microwave nearly one mugful of whole milk in a jug till boiling. In your mug, put a tablespoon of cream, 1 teaspoon of cocoa and 1 teaspoon of dextrose, and mix thoroughly while the milk is heating. Pour in the milk and stir - yum!
Adjust the amounts to suit yourself.
True chocolate devotees have their hot chocolate made with half milk half cream....