Blood Orange Tart

For the pastry: put the flour in a mixing bowl and rub in the the butter until the mixture resembles breadcrumbs. Add the caster sugar and egg and mix to a dough. If it is too stiff add a little cold water. Wrap in cling film and chill for 20 minutes.

Heat the oven to 190°C (170° fan) 375°F gas 5. Grease a deep 23 cm|9"springform flan tin.

Roll out the dough on a lightly floured surface. Line the tin with the dough, pressing it into the base and sides, leaving 2cm|1" of dough hanging over the edge. Line the dough with baking paper and baking beans. Bake 'blind' for 15 minutes. Remove the beans and paper and brush with egg white. Cook for a further 5 minutes.

Reduce the oven temperature to 180°C (160° fan) 350°F gas 4.

For the filling: beat together the orange zest, butter and sugar in a mixing bowl until light and creamy, then gradually beat in the eggs.

Put the mixture into a heatproof bowl over a pan of simmering (not boiling) water and cook, stirring for about 15 minutes until the mixture has thickened. Do not allow to become too hot or boil or the mixture will curdle.

Remove from the heat and stir in the orange juice.

Pour into the pastry case and bake for about 20 minutes until barely set. Cover with cling film and set aside to cool.

Heat the grill

For the topping: arrange the orange slices on the cooled tart and sprinkle over the demerara sugar.