Apricot Hazelnut Vanilla Tart with Rosemary

Preparation of the hazelnut shortcrust pastry
Mix the powders with the cold butter cut into cubes and the hazelnut oil. When there are no more lumps, add the egg white. Stop mixing as soon as a homogeneous dough is obtained. Roll out to 3 mm thickness between two guitar sheets or parchment paper. If necessary, put it back in the freezer several times so that the dough cools down and is easier to roll out. Reserve in the freezer.

Lining the tart base
Using a tart ring, cut out the tart base like with a cookie cutter. Next to it, make strips of dough, 3 cm wide, at least as long as the ring. Freeze. Once the dough is frozen, butter the tart ring. Place the shortcrust pastry disc on the baking sheet (with parchment paper). Press down firmly so that the disc touches the sheet. Place the ring around the pastry disc, then place the pre-cut strips of dough inside against the edges. Trim off the excess dough with a knife: press the back of the knife against the ring and then remove the excess dough. Freeze the dough. Once frozen, bake at 150°C (300°F) with fan-assisted heat for 25 minutes. For even baking, you can turn the tray halfway through.

With the leftover shortcrust pastry: make shortbread cookies and bake in the same way.

Crush the hazelnuts.
Whisk together the 130 g of egg whites, oil, water, hazelnut powder, flour, and baking powder. Whip the remaining egg whites to soft peaks with the sugar.
Fold 1/3 of the whipped egg whites into the mixture without caution. Then gently incorporate the remaining 2/3 with a spatula, taking care not to break them. Pour the batter onto a 40 x 60 cm baking sheet. Sprinkle the crushed hazelnuts over the biscuit. Bake at 180°C (356°F) for about 18 minutes.
Turn the biscuit halfway through baking to ensure even cooking. The result is a very airy and flexible biscuit. The offcuts of the chiffon cake can be used for verrines, for example, or frozen for use in another recipe.

Rehydrate the gelatin sheet in cold water. Partially melt the white chocolate (some beans are still visible). Mix a small part of the water with the potato starch at room temperature. Set aside. Heat the rest of the water to between 85 and 90°C.

Add the vanilla doses and let melt. Pour part of the hot water over the water-starch mixture. Put everything back into the pot, bring to a boil. Stop the cooking and add the rehydrated gelatin. Pour over the melted chocolate in three parts and emulsify with a spatula.

Finish the emulsion with an immersion blender for 1 minute. Add the cold cream. Blend again for 1 minute with the blender. Allow to crystallize in the refrigerator for at least 12 hours at 4°C. The ganache should be whipped at the time of the tart assembly.

Equivalence with Dulcey 35%: Replace the white chocolate with 281 g of Dulcey 35% and do not add vanilla. The result will be slightly sweeter.

Blend the apricots to make a puree, add the rosemary and lemon juice. Allow to infuse in the refrigerator for 24 hours, ideally vacuum-sealed, or covered directly with cling film.

It is possible not to use rosemary or to replace it with lavender or thyme. You can also roast the apricots with olive oil (or hazelnut oil) and a bit of honey for added indulgence. This will give a sweeter touch to the recipe.