Preheat the oven to 200'C.
Mix the flour, butter, salt and 70g of sugar in a bowl until smooth.
Add 2 egg yolks and mix well.
Transfer the shortbread pastry to a sheet of baking paper, cover with a second sheet and roll out the pastry to a thickness of 5mm.
Set aside in a cool place for 15mins and then bake for 15-20 minutes.
Take out of the oven and use a pastry cutter to make individual shortbread biscuits.
Cut the chocolate into pieces.
Bring the milk and cream to the boil.
Beat the 4 egg yolks with 80 g of sugar until they become white and form a light mousse.
Add the milk and cream to the egg yolk mixture, then return to the heat.
Stir constantly and cook until the mixture reaches 84'C - the cream should coat the back of a spoon.
Pass the cream through a sieve on to the chocolate pieces.
Mix well, ensuring that all of the chocolate is melted, then pour into individual serving glasses.
Place in the fridge for at least 45 minutes.
Mix the espresso coffee, the chicory, the cream and 20g of sugar in a bowl.
Transfer everything into a siphon and keep in a cool place until ready to use.
Add a gas cartridge to the siphon.
Cover the chocolate cream with the coffee emulsion and garnish with a shortbread biscuit to serve.
«If you can, make the chocolate cream a day in advance and allow to set overnight.»