The mousse is best eaten the same day and should ... online and at some supermarkets), a coating of finely chopped nuts mixed with some cocoa powder is a good alternative.

Whisk in cocoa powder, instant espresso ... fat will begin to separate and it will look curdled. Divide chocolate mousse into serving bowls or glasses and refrigerate until ready to serve.

If you want it to look extra special, you can pipe the mousse in. Serve with whipped cream if desired, with an extra sprinkling of hazelnuts on top and an optional dusting of cocoa powder.