A classic French lemon tart fit for a king, as served up to the French monarchy in the nineteenth century. A delicious mixture of sweet and sour, with a silky filling encased in a crisp pastry shell. An impressive yet easy to make dessert.
Sift the flour and icing sugar into a large mixing bowl.
Using your fingertips, gently rub the cubes of butter into the flour and sugar until the mixture resembles breadcrumbs. (You can do this step in a food processor if you have one.)
Stir in the lemon zest. Add the egg, then gently work the mixture together until it forms a ball of dough (you may need to add a little water, just 1 teaspoon at a time, if the egg isn’t quite enough). Remember not to work the pastry too much at this stage or it will become tough and chewy, not crumbly and short.
On a surface lightly dusted with flour, shape the pastry into a disc, wrap it in baking paper or wax paper, then chill for at least 30 minutes. Heat the oven to 190°C/170°C fan/375°F/Gas 5.
Tip out the pastry onto a surface lightly dusted with flour and roll it out to a circle about 30cm in diameter and about 3mm thick (about the thickness of a £1 coin). Use the pastry to line the 23cm fluted loose-bottomed tart tin, pressing it into the flutes around the edge. Leave the excess pastry hanging over the sides of the tin (this helps prevent it shrinking during baking). Prick the base of the pastry with a fork. Chill in the fridge for 20 minutes.
Line the pastry case with baking paper and fill it with baking beans. Place the tin on a baking tray and bake the tart case for 15 minutes. Then, remove the baking beans and paper and bake for a further 15 minutes. Remove from the oven.
While the pastry is baking, make the filling. In a large bowl, whisk together the eggs, lemon juice and zest, orange juice and zest, double cream and sugar using a balloon whisk, until combined.
Once the pastry case is baked and you’ve removed the beans and paper, reduce the oven temperature to 160°C/140°C fan/315°F/Gas 3. Pour the filling into the tart case and bake for 25–30 minutes, until just set with a slight wobble in the centre.
Remove from the oven and leave to cool at room temperature, then chill until ready to serve.