1. In a medium saucepan, bring the cream and 200ml of the milk to a simmer; do not boil.
2. Remove from heat. Add vanilla essence.
3. In a small bowl, mix sugar, corn flour and remaining milk.
4. Pour into warmed milk and whisk well.
5. Whisk eggs well and pour slowly into milk mixture while whisking continuously.
6. Return the saucepan to medium heat and mix in chocolate.
7. Cook until the custard thickens.
8. Serve with extra whipped cream and chocolate shavings.
9. Keep refrigerated for up to one week.
Recipe by Grace Stevens, for Expresso.