tangy lemon squares

Makes 16

Preparation time 25 minutes, plus chilling and cooling

Cooking time 45 minutes

100 g (3½ oz) plain flour, sifted, plus extra for dusting

175 g (6 oz) chilled unsalted butter, cut into pieces

40 g (1½ oz) icing sugar, sifted, plus extra for dusting

1 teaspoon cold water

1 egg yolk and 6 eggs, beaten

300 g (10 oz) caster sugar

finely grated rind and juice of 4 lemons

Put the flour and 50 g (2 oz) of the butter in a food processor and blend until the mixture resembles breadcrumbs. Add the icing sugar, measurement water and egg yolk and blend to make a soft dough. Wrap in clingfilm and chill for at least 30 minutes.

Roll out the dough thinly on a floured surface to a 21 cm (8½ inch) square. Fit into a 20 cm (8 inch) square loose-based cake tin or shallow baking tin, pressing the pastry down firmly around the edges. Bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 15 minutes. Remove from the oven and reduce the oven temperature to 180°C (350°F), Gas Mark 4. Put the whole eggs, caster sugar and remaining butter into a saucepan and heat gently until the sugar has dissolved. Stir in the lemon rind and juice and cook, stirring, for 5–10 minutes until the mixture has thickened slightly. Strain through a sieve into a jug and pour over the pastry.

Bake for 20 minutes until just set. Leave to cool completely in the tin. Transfer to a plate, dust with icing sugar and serve cut into 16 squares.

For meringue-frosted lime squares, prepare and bake the pastry as above. Make the filling, replacing 3 of the lemons and the lemon rind with the rind and juice of 4 limes. Bake and leave to cool. Put 2 egg whites, 100 g (3½ oz) sifted icing sugar and a pinch of cream of tartar into a thoroughly clean heatproof bowl and rest it over a pan of gently simmering water. Whisk with a hand-held electric whisk until thickened. Remove from the heat and whisk for a further 2–3 minutes until softly peaking. Use a palette knife to spread the frosting over the filling.