A delicious chocolate treat

I have been making the most delicious chocolatey custards in the microwave lately.  They are great for breakfast or as a snack.  You need:

a cup of milk
an egg
a heaping teaspoon of cocoa
sweetener - I use Splenda, but you can use any other low-cal sweetener
vanilla essence (optional)

1. Heat the milk in the microwave for 2 minutes
2. Meanwhile, using an immersion blender, mix the remaining ingredients in a small bowl or jug.  You could use a regular blender instead.
3. Blend in the hot milk.
4. Return to the microwave for 7 minutes at 20% power.
5. Leave to stand a couple of minutes.

I sometimes overcook mine, in which case I give it a couple of zaps with the blender to give it a custardy texture again.  If your microwave runs very hot, this might happen to you as well.