Chestnut Yule Log

Separate the egg yolks from the whites and whip each one separately. Beat the whites with half of the sugar, and the yolks with the remaining half. Continue beating until the whites form a glossy meringue and the yolks become very pale and reach the ribbon stage.

Sift the flour together with the ground almonds. Gently fold the yolk mixture into the meringue in batches, taking care not to deflate it. Add the dry ingredients carefully, folding until just combined.

Spread the batter onto a baking tray lined with a silicone mat and bake at 170 °C (340 °F) for about 10 minutes, or until lightly golden. Let cool completely, then trim the sheet to the size of your mold using a ruler.

Bring the lemon juice to a boil, then set aside. Whisk the eggs with the sugar, then pour the hot lemon juice over the egg mixture while whisking constantly. Return the entire mixture to the heat and cook until it reaches 90 °C (194 °F).

Cool the mixture slightly, then add the butter cut into cubes. Blend well, emulsifying with an immersion blender. Cover the cream in an airtight container and chill.

Once the génoise sponge is ready, spread the lemon cream over the top and freeze.

Mix the sugar with the pectin and set aside in a bowl while you prepare the crémeux.
Heat the fruit purée, cream, and egg yolks to 45 °C (113 °F), then whisk in the sugar–pectin mixture.

Cook the mixture to 85 °C (185 °F), whisking constantly. Remove from the heat and let it cool to 40 °C (104 °F). Once it reaches 40 °C, add the butter cut into cubes and blend with an immersion blender until smooth and fully emulsified.

Cover the surface directly with plastic wrap and chill in the refrigerator. Freeze a portion of the crémeux in a tube mold (I made a mold using a sheet of plastic and sealed it with aluminum tape). Keep the rest of the crémeux refrigerated for decoration.

Begin making the mousse only once all the other components are already frozen.
Hydrate the gelatin sheets in very cold water.

In a bowl, mix the chestnut purée, chestnut cream, and rum until smooth and fully combined. Heat the 35 ml of cream, then add the hydrated gelatin, stirring until completely dissolved. Incorporate this gelatin mixture into the chestnut mixture and blend until homogeneous.

Whip the remaining cream to soft peaks, then gently fold it into the chestnut mixture, taking care not to deflate it.

Fill the dessert mold, making sure to coat the sides. Insert the previously frozen crémeux in the center, then cover with more mousse (I added pieces of marron glacé to the mousse). Finish by placing the génoise base with the lemon cream on top. Transfer to the freezer until fully set.

Once the entire Bûche de Noël is frozen (at least 12 hours in the freezer), begin preparing the glaze.

Hydrate the gelatin in plenty of cold water. Bring the water, sugar, and glucose to a boil. Pour the hot syrup over the white chocolate and cream, then add the hydrated gelatin. Blend with an immersion blender without incorporating air. Let the glaze cool to 37–35 °C (98–95 °F) before using.

Unmold the frozen mousse, and once the glaze reaches the proper temperature, glaze the log. Decorate the top with the remaining chestnut crémeux, small meringues, and a few pieces of chestnut. Allow the dessert to rest for three hours in the refrigerator before serving, so it reaches optimal texture and flavour.