Heat the egg whites with the sugar in a bain marie at 60°C. Whip until firm. Pipe little balls. Bake at 80°C for 2h.
Mix the yuzu lemon purée with half of the sugar (1) very thoroughly. Combine the rest of the sugar (1) with the custard powder and dessert jelly. Add the yolks, eggs and purée/sugar (1) mixture. In a saucepan, add the lemon juice and the previous mixture. Bring to a boil while stirring. At the end of the cooking time, add the cold butter in small cubes and mix for 5 minutes. Pour into 2 cm diameter Silikomart® spherical moulds. Keep in the freezer. Gently whip the Elle & Vire Excellence Whipping Cream, 35% fat with the sugar (2), then dip the yuzu core so that it is properly coated. Put back into the freezer.
Mix the gelatin with the water. Create a base with the chestnut paste and the chestnut cream. Heat the cream (1) to 50°c and add the gelatin, mix well until the gelatin melts. Stir the gelatin into the chestnut base and mix all together. Heat the yolks and chestnut syrup in a bain-marie at 80°C. Whip until the mixture forms a ribbon when you lift the whisk. Whip the cream (2). Mix the pâte à bombe with the chestnut base, then add the whipped cream. Assemble in the 4.5 cm diameter Silikomart® balls.
Make a light hazelnut butter without straining. Let it cool slightly before use. Mix the icing sugar with the ground hazelnuts, the ground almonds, the buckwheat flour and the baking powder. Add the egg whites and trimoline. Mix briskly. Add the lukewarm hazelnut butter and the Golden Delicious apples, cut into small cubes. Polin oven: preheat the oven to 220°C and bake at 200°C.
Mix the chestnut paste with the chestnut cream. Temper the butter cream and stir it into the mixture. Pipe it using a pastry bag with a bird nest nozzle.
Arrange the chestnut ball with the yuzu core on the buckwheat apple financier. Pipe the chestnut coating onto the chestnut ball. Decorate with little meringues and small pieces of glacé chestnut with a shimmery finish. Finish with a chocolate decoration.