Chestnut and Blackcurrant Tart by Sébastien Bouillet

Place the soft butter and icing sugar in the bowl of a stand mixer fitted with the paddle attachment and mix on low speed. Add the vanilla seeds, the beaten egg, the sifted flour and the fleur de sel, mixing between each addition until a smooth dough forms.

Wrap in cling film, shaping into a flattened rectangle, and refrigerate overnight.

The next day, roll out the dough to 2–3 mm thickness using a rolling pin. Lightly prick the dough with a fork and cut out a circle slightly larger than your 22 cm (8.7 in) diameter ring. This dough warms up quickly and can become tricky to handle. Don’t hesitate to return it to the refrigerator for a few moments, for example after rolling it out…

Place the dough in the ring (the holes made with the fork should face downwards).

A few tips for lining a tart ring: bring the dough to the inside of the ring, and using your index finger, create a right angle all the way around the dough. Form a slight lip on the inside, roll the rolling pin over the dough and remove the excess. Create a neat edge that rises up by pinching the dough (video tutorial available).

Place in the freezer while you preheat the oven to 170°C / 340°F. Ideally, the lined ring should be kept refrigerated for a few more hours, but this is not always possible…

Place a sheet of baking paper inside and add baking weights or dried beans to blind bake the pastry.

Bake for 25–30 minutes (in the photos, you can see that my tart shell is not cooked enough…).

Remove from the oven and leave to cool on a rack.

Once the tart shell is cooked and cooled, use a microplane grater to smooth any imperfections.

Meanwhile, melt the white chocolate in a bain-marie. Using a pastry brush, apply a thin layer of melted white chocolate to the tart shell to make it waterproof and preserve all the crunchiness of the pastry.

Mix one third of the sugar with the NH pectin.

Heat the blackcurrant purée with the remaining sugar and the glucose.

Pour a little of the hot purée onto the sugar and pectin mixture and stir vigorously so there are no lumps.

Add this mixture back to the rest of the blackcurrant purée and bring everything to the boil. Reduce the heat slightly to avoid splashing and cook for 2 minutes, stirring regularly.

Transfer to a bowl and leave to cool, stirring often to prevent a skin from forming on the surface.

Place the bowl and the whisk attachment of your electric mixer in the freezer for at least 15 minutes.

Pour the cream and mascarpone into the bowl and begin whipping at medium speed, then as the cream starts to firm up a little, increase the speed. Gradually, the cream will begin to rise and stiffen.

Check the consistency from time to time by stopping the mixer and looking at the cream (it sets more quickly with a little mascarpone). It is ready once it is completely firm. If you turn the bowl upside down, it should not fall. Be careful not to over-whip the cream or you risk getting butter. You need to know when to stop.

Remember to add the icing sugar and the vanilla seeds when the cream is almost fully whipped.

Preheat your oven to 200°C / 400°F.

Melt the butter in a saucepan until it turns a hazelnut colour (stirring continuously). Leave to cool.

In a bowl, mix all the dry ingredients together, then add the egg whites and the blackcurrant purée.

Add the beurre noisette at room temperature.

Pour the batter into a 20 cm (7.9 in) diameter ring placed on a baking tray lined with baking paper.

Lower the oven temperature to 170°C / 340°F and bake for 12 to 15 minutes. The batter should have a light golden colour. Remove from the oven and leave to cool in the ring.

Soften the butter to a cream and add the chestnut paste little by little, scraping the sides of the bowl well to ensure a smooth, homogeneous mixture.

Incorporate the sweetened chestnut cream using the mixer.

Transfer the cream to a piping bag fitted with a vermicelli nozzle.

Pour the blackcurrant compote over the cooked sweet pastry base.

Place the blackcurrant financier on top and press down gently to adhere.

Cover with chantilly cream and smooth with a spatula to create a slightly domed surface in the centre.

Cover the tart with the chestnut filling.

Decorate the tart with small meringues and a few dots of chestnut cream (though you can also use marrons glacés).