The pastry: sift the flour into a bowl, add the butter and rub in with your fingertips until the mixture resembles breadcrumbs - you can use a food processor - is then stir in the armaments and sugar, and add the egg yolk and 2 tablespoons cold water. Mix with your hands on to the pastry comes together

Knead lightly on a floured surface then wrap and chill for about 30 minutes

Meanwhile preheat the oven to 200°C and pop in a baking sheet to heat up

Roll out the pastry 2 an 8 inch round and use it to line a 7 a half inch fluted loose base plan tin

Prick the base with a fork and line with greaseproof paper then fill it with baking beans

Place the tin on the preheated baking sheet and bake blind for 12 minutes. Remove the paper and beans and bake for a further 5 minutes

Remove from the oven and cool

Reduce the temperature of the oven to 150°C

Filling: but the lemon juice and rind into a jug which should come to about two thirds of the cup.

Blend the cornflour with a little of the lemon juice then gradually stir in the rest. Pour into a saucepan and add 2/3 a cup of water

Bring slowly to the boil stirring until smooth and thickened

Remove from the heat in beating the sugar and egg yolks, then add the butter, then spoon into the pastry case's

Meringue: whisk the egg whites until stiff, then gradually whisk in the sugar a tablespoon at a time until thick and glossy.Pile the meringue on top of the lemon filling spreading and swirling it with the back of a spoon

Bake for 30 to 35 minutes or until the meringue is golden and crisp