Here you go chocolate mousse, this is from my granddad's recipe book but I've updated the measurements.
120g dark chocolate, finely chopped
120ml double cream
2 tbsp rum, brandy, or Grand Marnier (or simply use 1 tsp grated orange rind)
2 eggs, separated
Grate or chop the chocolate finely and bring the cream up to the boil, turn off the heat, and add the chocolate. Stir until the chocolate is melted and then add the alcohol or orange rind (You could use orange juice or crushed raspberries). Let the mixture cool a little, and then beat in the egg yolks. Next whisk the egg whites until they form stiff peaks. Stir one quarter of egg whites into the chocolate mixture to loosen the it, and then carefully fold in the rest taking care not to knock all the air out. Spoon into little dessert bowls, glasses or espresso cups. Chill in the fridge for an hour or two until set.
Eggless version:
My version doesn't use eggs though because I'm allergic. I beat the cream with a teaspoonful of sugar till it's fairly stiff, adding the orange juice/crushed raspberries at the end. I melt the chocolate slowly over a bowl of hot water and stir in a bit of the whipped cream at a time, to cool it, keep it light and stop it splitting. I chill it in the fridge and serve it with some peeled and blanched orange segments or fresh raspberries.