Prepare the pastry: In a food processor, combine flour, salt, and butter until it resembles breadcrumbs.

Add sugar and pulse to mix.

Gradually add cold water (6 tablespoons) to form a dough.

Shape the dough into a ball, wrap it in cling film, and refrigerate for at least 30 minutes.

Divide the pastry into four equal portions.

Roll out each portion thinly on a floured surface.

Line four 10cm fluted tart tins with the pastry.

Rest the pastry-lined tins in the fridge for at least 30 minutes.

Preheat the oven to 180C/Gas Mark 4.

Prick the bottom of each pastry case with a fork, line with baking parchment, and fill with baking beans.

Place the tins on a baking tray and bake blind for 10 minutes.

Remove the beans and paper and bake for another 10 minutes, or until the pastry is cooked.

Cool slightly and brush with beaten egg yolk to seal.

Set aside.

For the chocolate filling: Melt chocolate and cream in a heatproof bowl over simmering water, stirring occasionally.

Remove from heat and let cool slightly, then mix in the egg yolks one at a time.

Divide the chocolate mixture among the cooked tart cases.

Bake for 3-5 minutes or until the filling has softly set.

Remove from the oven and allow to cool, then refrigerate.

For the hazelnut crumble topping: Blitz the hazelnuts in a food processor to a fine crumb.

Transfer the hazelnut crumbs to a mixing bowl.

In the food processor, combine flour and butter until the mixture resembles breadcrumbs.

Add the flour mixture to the hazelnuts, along with the caster sugar, and mix together.

Spread the crumble on a baking tray and bake for 15-20 minutes, or until golden brown, stirring halfway through to prevent sticking.

Let the crumble cool, then sprinkle it over the top of each tart and dust with icing sugar.

For the raspberry coulis: Blend all ingredients in a blender or food processor until smooth, then pass through a sieve to remove the seeds.

For the rippled Chantilly cream: Whip the cream with icing sugar and vanilla seeds to soft peaks.

Fold 2-3 tablespoons of raspberry coulis through the cream to create a rippled effect.

Keep refrigerated until ready to serve.

To serve: Place a small spoonful of plain cream underneath each tart to prevent sliding.

Add a quenelle of rippled Chantilly cream to the plate and serve the raspberry coulis in a small pouring pot.