A Thousand and One Layers of Indulgence

To make the beurre manié:
Mix the softened butter with the flour and spread it into a 30 × 15cm rectangle between two sheets of parchment paper. Leave to rest in the refrigerator for 2 hours.

To make the détrempe:
Mix the softened butter with the flour. Add the salt, then incorporate the vinegar mixed with water. Mix the dough carefully, without overworking it. Spread out in a 13 × 13cm square. Shape them into a ball, cover with film and leave to stand in the refrigerator for 2 hours

To make the pastry:
Place the rectangle of beurre manié in front of you, portrait-style. Place the square of détrempe in the lower half of this rectangle and fold the butter at the top. Then fold over the butter at the bottom and rotate the butter-dough by a quarter turn. Spread out the butter-dough again to a length of approx. 30 × 15cm on a thoroughly floured worktop. Fold over the top third of the dough and then the bottom third. Rotate again by a quarter turn. Cover with film and set aside at least 1 hour. Do another 2 turns in this way. Leave to rest in the refrigerator for another hour, then finish off with a final turn and store in the refrigerator ideally overnight.

Baking:
Spread out the puff pastry to a thickness of 2mm. Sprinkle with finely ground roasted hazelnuts. Bake at 410°F (210°C) for 15 minutes and finish baking at 345°F (175°C) until golden-brown.

Mix the eggs and sugar without beating too much. Bring the cream and milk to a boil and combine the two mixtures.
Heat the mixture to 185°F (84°C) and mix with an immersion blender until it is homogeneous.
Add the rehydrated gelatin and combine it with the melted AZÉLIA 35% chocolate in three stages. Use an immersion blender to blend the emulsion until it is perfectly combined.
Leave in the refrigerator for at least 6 hours before use.

Mix the water and gelatin in a container. Heat two-thirds of the whole milk in a saucepan.
Mix the potato starch with the remaining cold milk. Add this to the warm milk and let it thicken, whisking it all the while so it doesn’t stick to the pan.
Then add the rehydrated gelatin. Pour one-third of this mixture over the praliné and melted cocoa butter.
Mix vigorously with a whisk so its center looks elastic. Add another third the same way. Then incorporate the final third using the same method.
Add the cold whole cream, then blend with a immersion blender to perfect the emulsion.
Leave to stiffen in the refrigerator, preferably for 12 hours.

Bring the milk to a boil then combine it with the rehydrated gelatin.
Pour this onto the GUANAJA 70% chocolate, then emulsify the two.
Store in the refrigerator overnight.

ut the cooled puff pastry into 24 4 × 12cm rectangles using a bread knife.
Whip the praliné whipped ganache until it has a soft texture that is suitable for piping.
Using a piping bag with a 14mm nozzle, place the praliné whipped ganache on eight rectangles of cooled, cooked puff pastry, then make a few dabs of intense GUANAJA 70% gel.
Place a rectangle of cooked and cooled puff pastry over each of the eight garnished rectangles.
Use a piping bag with a 14mm nozzle to apply the AZÉLIA 35% crémeux.
Top the eight millefeuilles with another rectangle of puff pastry and sprinkle with cocoa powder.