Instant Chocolate Mousse

Normally you need to make chocolate mousse a good few hours, or better still a day, before you want to eat it so the egg yolk sets and the whisked whites permeate everything with air bubbles. Forget that: here we have no yolks, no whites, no whisking, no waiting. Lack of raw egg, incidentally, also means that you might be happier giving the mousse to small children, though I certainly feel they should not be the only beneficiaries.