Prep chocolate - If using chocolate blocks, chop it up with a large knife into bite sized pieces and place in a large (2.5 litre) heat proof glass jug or medium sized glass bowl.
Whisk egg yolks and sugar - For this recipe you will only need the egg yolks. Separate the eggs and add them to a medium sized heat proof bowl. Add the sugar, vanilla and salt and whisk on high-speed using an electric hand mixer until pale and thick. About 3-4 minutes.
Heat milk and cream - Add the milk and cream into a medium sized nonstick saucepan and heat on low until it begins to (barely) bubble very gently around the sides.
Cook Crème Anglais - Slowly whisk the hot milk into the egg yolk mixture. I do this in four batches. Then return it to the saucepan and stir with a spatula over medium-low heat. It will begin to thicken after a couple minutes. When it can coat the back of a spoon, take of off the heat. Do not let it boil it will curdle the eggs.
Pour into chocolate - Pour the hot mixture into the bowl or jug with the chocolate and cover with a plate to let it steam for about 5 minutes.
To get a super smooth mixture - Use a whisk to combine the melted chocolate with the milk mixture. If you want to get a silky texture, use a stick blender to blend until it becomes smooth and glossy. Make sure the blender is fully submerged ot it will add air to your creameux.
To set - Pour the filling into the tart. If it feels like it’s too much filling, just add as much as you can without it over spilling. Transfer back to the fridge (make sure it’s on a baking tray) and let it set completely for at least 5-6 hours. I do this overnight.