Heat the milk, water, salt, sugar and butter together and bring to the boil. Take off the heat and add the flour, all in one go. Stir briskly. Put back on the heat until mixture forms a soft ball and leaves sides of pan clean. Transfer to a basin, add the eggs very gradually. Pipe out a 15 cm length, using piping bag with no.14 nozzle and 15 cm length. Oven at 180°C (356°F), closed vent for 15 min (to allow the dough to rise), then opened vent for approx.
15 min until baked as desired.
Mix the ingredients. Flatten between two sheets (of greaseproof paper). Allow to harden in refrigerator, then cut up with a pastry cutter according to the size of the choux pastry and place on each éclair before baking.
Heat the milk, whip the egg yolks and sugar until white. Cook to make custard. Place in a mixer bowl and whisk until completely cold. Heat the sugar and water to 121°C (250°F), pour over the egg whites which have been whipped into ‘peaks’ and continue to whisk until cold. Add the butter cream to the custard and whisk. Add the Italian meringue and mix in.
Whisk the butter cream and the confectioner’s custard together. Add in the praline cream and hazelnut paste.
Prepare the syrup with the water, sugar and zest. Leave to stand for 15 min. Add the gelatine, then the juice. Filter. Pour into a film-lined frame or 5-mm-high container. Allow to set, then cut into strips the length of the éclair and 1 cm wide.
Mix the hazelnuts, egg white and 5 g of salt. Place in the oven at 150°C (302°F) for 14 min. Heat the sugar and water to 118°C (244°F), add the nuts and allow them to caramelise. Finally, add the hazelnut oil and salt. Turn out onto a silicon board, separate one by one.
Cut the top third off the éclair. Fill with a little praline cream, place the strip of Yuzu jelly on top. Using a fluted nozzle, pipe out the praline cream to form a spiral. Top with some caramelised nuts and yuzu zest en julienne (little sticks). Sprinkle icing sugar over 1/3 of the surface of the top of the éclair (in a triangle shape). Put the top back in place.