Delicious chocolate pastry cream

- Heat the milk in a saucepan without letting it boil. Meanwhile, in a bowl, beat the egg yolks with the sugar until smooth.

- Add the cornstarch to the egg yolk and sugar mixture and mix well. It is essential that there are no lumps. If necessary, use a strainer to make sure the cornstarch is fully integrated.

- Pour the hot milk little by little to the previous mixture while stirring.

- Return the mixture to the saucepan and cook over medium-low heat, stirring constantly, until thickened. This step requires patience, as the cream should thicken slowly to prevent lumps from forming. It usually takes about 10 minutes.

- When the cream has thickened, remove from the heat and add the chopped chocolate and butter. Stir well until it has melted and is completely incorporated. During this stage, it is essential to stir constantly so that the chocolate and butter are properly integrated and the cream acquires a smooth, silky texture.

- Transfer the cream to a bowl and cover with cling film, touching the surface to prevent a film from forming. Let cool to room temperature and then refrigerate until ready to use.