Sugar-free Spiced Cocoa Pie

For the pastry: sift the flour into a mixing bowl and stir in the salt. Rub in the butter until the mixture resembles breadcrumbs. Gradually add the water, a tablespoon at a time, mixing continuously until the mixture just comes together as a dough. Roll the dough into a ball, then wrap in cling film and chill for 1 hour.

Heat the oven to 200°C / 400°F. Grease a 36cm x 12cm / 14-1/2" x 5" rectangle tart tin

Roll out the dough on a floured work surface and line the tin. Prick the base of the pastry case several times with a fork. Cover the pastry with a sheet of non-stick baking paper and fill it with rice or dried beans. Bake for 20 minutes, until the pastry is pale golden. Remove from the oven and remove the beans and paper.

Reduce the oven temperature to 130°C / 275°F.

Put the chocolate, butter and stevia in a heatproof bowl over a pan of simmering (not boiling) water stirring until smooth and melted.

Mix the cocoa with the hot water, stirring until smooth.

Beat the eggs until frothy and stir in the chocolate and cocoa mixtures. Stir in the cardamom.

Pour into the pastry case and bake for 40-45 minutes until set.

To decorate: melt the chocolate in a heatproof bowl as before.

Arrange 2-3 glass jars on their sides a few inches apart on a baking tray and secure with sticky tape.

Cut a 14" strip of non-stick baking paper and fold in half lengthways.

Spread the paper with a thick layer of melted chocolate and lay it across the jars so that it curves. Freeze for 5 minutes until set. Peel off the paper and cut to size to fit across the tart.