1. Melt the chocolate and the butter in a bain-marie.

2. In a mixing bowl, beat the six egg yolks and sugar until the mixture forms soft peaks. Add the chocolate mixture and mix.

3. In another bowl, mix the egg whites with a pinch of salt until it gets foamy. With a spatula, add the eggs whites into the chocolate mixture.

4. Serve in a round bowl and cover the preparation with a plastic film.

5. Refrigerate for 24 hours.