How to make the pastry
To make the pastry, put the flour, lard and margarine in a bowl or electric mixer and rub in, or process, until the mixture resembles breadcrumbs. Add just enough water to bind the breadcrumbs together. Tip out onto a lightly floured work surface and knead lightly until it comes together in a ball.
Roll out the dough to line a 20 cm (8 in) loose-base flan tin. Refrigerate to rest for 10 minutes. Meanwhile preheat the oven to 190°C/375°F/Gas mark 5. Line the pastry in the tin with baking paper and fill with baking beans or weights. Bake blind for 10 minutes, then remove the paper and baking beans and bake for another 5 minutes. Leave to cool. Lower the oven temperature to 170°C/310°F/Gas mark 3½.
How to make the lemon pie filling
To make the filling, put the sugar, egg yolks, lemon zest and juice and water in a saucepan. Place over a medium heat and bring to a rolling boil for 5–10 minutes. Remove from the heat. Stir the cornflour paste into the hot lemon mix. Allow to thicken. Pour into the baked pastry case.
How to make the meringue
In a bowl, beat the egg whites using an electric mixer and whisk, until thick peaks form. Leave the mixer turned on and add the sugar gradually. Keep mixing until the egg whites are thick and glossy. Pour on top of the lemon filling. Bake for 20 minutes, or until the meringue is hard to the touch.
Recipe taken from Britain's Best Bakery, available from New Holland Publishers, RRP: £24.99.