Step 1

Preheat the oven to 175°C (350°F). Prepare 6 loose base mini tart tins (9cm diameter).

Step 2

To make the pastry, sift chestnut and plain flours into a large bowl. Add almond and coconut flours and salt and mix everything. Add cubed butter and rub into the dry ingredients using your finger tips until the mixture resembles breadcrumbs.

Step 3

Make a well in the middle of the flour mixture, add an egg yolk, agave syrup and grated orange zest. Work the mixture together to form a ball of dough. Wrap the cling film and place in fridge to rest for about 30 minutes.

Step 4

Take the dough from the fridge and roll out the pastry 2 - 3 mm thin on a floured work surface and cut 6 rounds. Line the tins with the pastry and use your hands to gently press the dough into the tins. Prick the dough with a fork and then place tins in a fridge for about 15 minutes.

Step 5

Bake in the oven for about 10 - 12 minutes. Leave the pastry crust for 10 minutes in the tins and then remove them to wire rack.

Step 6

For the filling, chop the chocolate into smaller pieces using a serrated knife.

Step 7

Heat the whipping cream in a saucepan over a medium heat for about 2 - 3 minutes or until it starts to simmer. Pour it over the chocolate, leave for 1 - 2 minutes, then stir until it has completely melted. Add butter and stir again until you get a smooth texture. Set aside to cool for 10 minutes.

Step 8

Pour the chocolate filling into the pastry cases and leave to settle at room temperature for 10 minutes. Refrigerate until set. Just before serving sprinkle with some shaved chocolate.