Break the dark chocolate in (small) pieces and use a bain-marie to melt the chocolate. Stir frequently. As soon as about 50% is melted took the chocolate out of the bain-marie and stir as long as the rest is melted. Don't cook the chocolate!
Let the melted chocolate rest on your kitchen counter. It should cool down to a slightly warm mess at room temperature.
In the meantime: whip the whipping cream with the handheld electric mixer until stiff. Put it in the fridge.
Separate the eggs.
Whip the egg whites until stiff and put it in the fridge.
Whip the egg yolks, the sugar and a pinch of salt with the handheld electric mixed until creamy.
Add the slightly warm chocolate to the egg yolk mess and mix with an egg whip until evenly distributed.
Add the whipped cream and mix with the egg whip.
Add the stiff egg whites with a large spoon and fold in carefully.
Put the mess in a bowl resp. in small bowls or glasses and let it rest in the fridge until serving - at least 4-6 hours or even overnight.