My mum used to make a diabolically good dark chocolate mousse with just 3 ingredients.
She would gently melt dark chocolate, and mix it with egg yolks that had been beaten with a little liqueur. Then she would fold it into stiffly-beaten egg whites, pour into little glasses, and leave to set.
Diabolically good 
Question: could I do the same with white chocolate? All the recipes I can find for white chocolate mousse include double cream or whipped cream. Is there a technical reason for this?
I can't experiment. No time. I have one chance to get it right, and I have to make it tomorrow.