In a saucepan heat the milk, sugar, cocoa, chocolate and salt over a medium heat until the chocolate is melted. Stir continuously.

In a bowl, add your egg yolk and a bit of the warm mixture to heat up the egg. This prevents the egg from coagulating when added to the warm mixture.

Once the egg has been warmed, whisk it into the remaining hot chocolate.

Continue cooking the hot chocolate over a medium heat for 5 min. Stir continuously to prevent it from burning.