Lemon Meringue Pie

Pre-heat the oven to 180℃/340℉/gas 4.

Measure the flour and butter into a food processor and blejd together unitl the mixture ressembles find breadcrumbs.
Add the icing sugar, egg and one tbsp of water and whizz again until combined to a ball.

Tip the pasytry onto a work surface and roll out to a 3mm thickness.
Use the roling pin to lift the pastry up and transfer it to line a 23cm/9inch loose-bottomed flan tin. Be careful not to stretch the pastry as you tuck it into the corners.
Cover in cling film and place in the refrigerator to chill for 30 minutes.

Take the pastrylined tin out of the refrigerator and trim the excess patry.
Press the top edge of the pastry so that it stands slightly higher than the top of the tin.

Line the pastry case with parchment and fill with baking beans. Bake for about 15 minutes then remove the beans and parchment and return to the oven for a further 5 minutes.

Remove from the oven and reduce the temperature to 170℃/340℉/gas 3 1/2.

Mix the lemon sest and juce with the corn flour and stir to for a smooth paste.
Measure 450g of water into a pan and bring to a boil. Add the lemon corn flour mixture to the hot water and stir over the heat until the mixture has thickened, then remove from the heat.

In a bowl mix together the sugar and egg yolk and carefully whisk into the lemon mixture in the pan.
Stir over a medium heat until thickened.
Set aside for a few miutes and then pour ingo the baked pastry case.

Whisk the egg whites in a free-standing mixer until soft-peaks form when the whisk is removed. Add the caster sugar a little at a time, stil whisking until the meringue is stiff and glossy. Add the corn flour a nd whisk again.