Whisk the dry base: In a medium, heavy-based saucepan, combine the sugar, cocoa powder, cornflour, and salt. Use a balloon whisk to break up any lumps until the mixture looks like a fine, dark powder with no streaks. The smell of cocoa will be the first sensory clue that you’re on the right track.

Incorporate the egg yolks: In a small bowl, lightly beat the egg yolks. Add about 100ml of the milk to the yolks and whisk until smooth. Pour this yolk mixture into the dry ingredients in the saucepan, whisking constantly. You’ll see a thick, dark paste form—don’t worry, this is exactly what we want.

Add the remaining milk: Gradually pour in the rest of the milk while whisking continuously. The paste will loosen into a thin, liquid batter the colour of rich dark chocolate. Listen for the gentle slosh of the liquid against the pan as it comes together.

Cook over medium heat: Place the saucepan over medium heat and whisk constantly. Do not walk away. Within 3 to 5 minutes, you’ll notice the mixture beginning to steam and then thicken. You will feel the whisk meet resistance, and the sound will change from a liquid swish to a thicker, slower thump against the sides of the pan. The first large bubble breaking the surface is your signal.

Simmer and finish: Once the first bubble appears, continue whisking for exactly one minute more. This cooks out the raw cornflour taste. Remove the pan from the heat. The pudding will look glossy and thick, almost like a soft custard, and will coat the back of a spoon heavily.

Add the chocolate and butter: Immediately add the chopped dark chocolate, cubed butter, and vanilla extract. Whisk gently until everything is melted and fully incorporated. The mixture will become even shinier and smell intensely of melted chocolate. The texture should be completely smooth and velvety.

Strain for perfection: For a truly restaurant-worthy finish, pour the hot pudding through a fine-mesh sieve into a clean bowl. This removes any tiny lumps that might have formed. You’ll be left with a completely silky, unblemished cream.

Portion and chill: Divide the pudding evenly among four serving glasses or small bowls. Tap each glass gently on the counter to settle the pudding and release any trapped air bubbles. Cover each with cling film, pressing it directly onto the surface to prevent a skin from forming. Refrigerate for at least 2 hours, until completely set and chilled. The texture will be firm yet wobbly, like a perfect panna cotta.