Awww, then you missed something. ^^
Pour about four teaspoons of chocolate in the mug. Fill it with about ten teaspoons of milk and stir the mix until the chocolate turned into a smooth mass. Then fill the rest of the mug with milk and heat it in the microwave until it's hot.
Slice the apple into bite-size parts. Now dip a slice nearly all the way into the mug and make sure you keep it a few seconds in it to let the liquid soak into the apple slice.
And enjoy! :)