1. Heat up the chocolate and butter (ideally in a microwave) and stir together. Set aside to cool. 2. In a saucepan, heat the double cream up, not too fast, until it is pleasantly warm. 3. Add the sugar, stirring in gently until dissolved. Set aside to cool. 4. Once cool, whisk in the egg yolks and then the cream/sugar mixture, until quite thick and fluffy. 5. Fold in the melted chocolate/butter mixture gently and until well mixed. Try and keep the air bubbles in. 6. Pour into your container, stir, and put in the freezer to start to set. 7. After one hour, give the mixture a gentle stir and leave to freeze again. 8. Depending on how cold you have the freezer it can take anywhere from an hour to five hours to set to how you like it. Enjoy the richness!