I learned this from a ship's Captain who asked me at dinner once if I knew how to make colloidal sauces.
Ingredients per serving:
1 oz milk chocolate
1 egg
1oz whipping cream.
Trader Joe's 1 lb milk chocolate bars are great for this.
So I make enough for 6 people. You really should not try less.
Separate the eggs and refrigerate the egg whites.
Melt the chocolate but control the temperature to below 140 deg F. Set aside but keep it close.
Use a double boiler (preferably copper) to congeal the yokes to a sauce (like making hollandaise sauce). Stir constantly and vigorously. Do not over heat or work it to long. Be careful not to make scrambled eggs.
When egg yokes have thickened, fold melted chocolate and egg yokes together.
Whip cream to peaks.
Whip egg whites to peaks. As an optional extra you can add in an envelope of Knox clear gelatin to the egg whites. It will help keep the mousse stiff longer.
Fold the chocolate/yoke mixture into the whipped cream using a flexible spatula.
Then fold the chocolate/yoke/whipped cream into the egg whites.
It's important to fold and not stir. Stirring will cause the mousse to collapse.
Spoon into tall champagne glasses, and refrigerate until ready to serve
Add a little more whipped cream and garnish with powered chocolate or/and a mint leaf.
It took me a few tries to master this so don't beat yourself up if it doesn't come out at first.