1. Combine the egg yolks and sugar in a medium heatproof bowl. Place over a medium saucepan of simmering water. Using an electric beater whisk constantly until the mixture is thick and pale. Remove the bowl from the pan, add the vanilla essence and whisk for 10 minutes or until cooled to room temperature.
2. Bring the milk to a simmer in a small saucepan over medium heat. Place the chopped chocolate in a medium heatproof bowl and pour the milk over. Set aside for one minute, then stir until smooth.
3. Using the electric beaters whisk the cream in a medium bowl until soft peaks form.
4. Add the chocolate mixture to the egg yolk mix and stir until well combined. Use a large metal spoon to fold in 1/2 the cream until almost combined...then fold in the remaining cream.
5. Pour the ice-cream into a 1.25 litre airtight container. Freeze for 8 - 10 hours or until firm. (NOTE: if you have an ice-cream maker, pop the mixture into here).
