Break up chocolate into small pieces and put it in a bowl

In a separate bowl, add the egg yolk and give it a quick whisk

In a thick-bottomed saucepan, add the cream and the erythritol and heat it over a low flame. Also add in a few drops of the vanilla extract.

Bring the cream and erythritol mix just to a boil, while stirring continuously to prevent scorching.

As soon as the first bubbles appear in the cream, take it off the heat.

Add a few drops of the hot cream to the egg yolk and whisk it in. This is called tempering, and it's done so the boiling cream doesn't turn the yolk into scrambled egg.

Add a new drops at a time and whisk. Then add the entire cream to the egg yolk and give it all a good mix.

Put the egg and cream mix back into the saucepan and put it on a low heat. This is your custard.

Keep stirring the custard, until you start to see it thicken. Watch it carefully at this point, it shouldn't become too thick. It's done when it just coats the spatula or the back of a spoon.

Immediately take the custard off the heat and pour it over the chocolate pieces. Let sit for a minute, then whisk it all together until you get a thick, glossy pudding.

If the chocolate feels a bit too thick, add a bit more cream to loosen it up. Also add in a pinch of salt and whisk

Divide among two ramekins or cups and let it set in the refrigerator for about 30 mins.

Top with a bit of whipped cream or creme fraiche and serve. It's even better with a bit of berry compote and cream.