We had some hot chocolate on my camping trip and guess what! It separated in chocolate water, chocolate goop, and chocolate film, also it smelled gross.
I mix the mix into the milk while the water is boiling, then pour in the water and stir it all together. Then I add whipped cream or cool whip if I'm in the mood, or just stuff it with marshmallows. Sometimes I can even add a few spices like cinnamon and stuff on top