Chop the dark couverture and keep it aside

Mix corn starch, cream, salt and cocoa powder in a bowl. Add egg yolk and mix it well. Keep it aside

In a pot, add milk and sugar. Warm it up until little bubble on the edge of pot.

Slowly pour the warm milk into the cocoa mixture while whisking it as well.

Pour back all the mixture into the pot.

On the low-medium heat, cook the pudding mixture. Add the gelatine into it. Mix it well.

Cook it until the mixture boiling up and thicken. Whisking it evenly.

Switch off the heat. Add the chopped dark chocolate and let it melted with the mixture. Whisk it until the dark chocolate incorporate into the pudding.

Pour the pudding into a bowl or container. Cover it with plastic folio to prevent the skin build up.

Cool it down overnight. Ready to serve for the next day.