Refrigerate the salmon fillet. Combine all the gravlax ingredients. Cover the salmon with the mixture, taking care not to put too much on the stomach or tail. Vacuum seal in the salt mixture and refrigerate for 16 hours. Remove the seasoning and rinse thoroughly, soak in iced water if a crust of salt forms on the surface. Drain, dry with kitchen roll then cover with the previously combined marinade ingredients. Marinate under a vacuum seal for at least 48 h. Cut 5 mm thick slices of salmon fillet. If necessary, place between two sheets of cling film and flatten in order to obtain the desired thickness. Cut into a 5 mm brunoise.
Blend the cream cheese, thin with the cream. Add the yuzu juice, lemon peel and grated horseradish. Correct seasoning with salt and Espelette pepper. Fill each glass with cream cheese mousse to a height of 4 cm or 12 g of the mixture. Tap the glass on the work surface to even out the mousse then freeze.
Cut the lemon peel into a 1.5 cm long thin julienne. Blanch 3 times then candy in lemon and yuzu juice with the sugar and water.
Heat 1/10th of the chicken stock. When it comes to the boil, add the dill and the gelatine and blend. Add the rest of the chicken stock, place over a bowl of ice and skim thoroughly. Using a piston funnel, put the mixture on top of the cream cheese mousse (5 mm). Refrigerate to set.
Make puff pastry that has been coloured with squid ink or black food colouring. Give 6 turns, roll out to a thickness of 1 mm (using a dough sheeter), rest in the freezer. Use a knife to cut out triangles of 4.5 cm x 1 cm. Bake in the oven at 170°C between two sheets of greaseproof paper and two baking sheets until crisp. Set aside in an airtight container with calcium chloride.
Add a little marinade to the salmon brunoise to intensify its flavour before delicately positioning in a dome shape on top of the jelly. Decorate with two small strips of candied lemon peel in a cross shape, a triangle of puff pastry and a sprig of dill.