Perfect Lemon Meringue Pie

Instructions

Pastry:

Combine the flour, butter sugar and salt in the bowl of a food processor with the blade attachment fitted. Process until the mixture resembles crumbs. Add the egg and the water and run the processor until the mixture forms a dough and clumps together. Turn out onto the benchtop and knead briefly to form a dough.
Grease a large, deep-sided tart tin, then dust the benchtop with flour. Roll the dough out to a circle larger than the tin, dusting the dough with flour and turning as you go so that it doesn’t stick. Drape the dough over the rolling pin and transfer to the prepared tin.
Gently press the dough into the tin, avoiding stretching it as this can make it shrink later. Trim off any overhang and wrap in clingfilm. Prick the pastry all over with a form and transfer to the fridge or freezer for 30 minutes.
Heat the oven to 180°C / 350°F / Gas 4 and place a baking tray in the middle of the oven. When the tart has chilled, remove from the refrigerator, scrunch up a large piece of baking paper and use it to line the pastry. Top the baking paper with a large sheet of tin foil, pressing against the side and into all the crevices. Bake in the preheated oven for 20 minutes, then carefully remove the tinfoil and baking paper and bake for another 20 minutes. If the base starts puffing up, use a fork to gently poke a few air holes into it.
When the base has cooked, remove from the oven and set aside to cool. If there are any rips or tears, gently patch them up with the reserved pastry dough while the tart case is hot.

Lemon Filling:

Whisk egg yolks in a medium bowl and set aside. In a medium saucepan whisk together the sugar, cornstarch and salt. Add water, lemon juice and zest and whisk until smooth. Place over medium heat and whisk until the mixture is very thick, this will take 5-7 minutes.
Pour a little of the hot mixture onto the eggs, whisking well. Add the egg mixture back to the saucepan, whisking to combine, then continue to cook for 2-3 minutes, stirring continuously until the mixture has thickened and is well combined. Remove from the heat and stir through the butter until melted. Pour into the cooked pie crust, smooth the top and set aside.

Italian Meringue:

Stir together sugar and water in a saucepan over medium heat until dissolved. Bring to the boil and cook without stirring until the mixture reads 116°C/ 240°F on a candy or sugar thermometer. Meanwhile, beat the egg whites to firm peaks in a stand mixer. When the sugar syrup is hot, gradually pour it into the beaten egg whites, whisking all the time.
Add the cream of tartar or lemon juice and vanilla extract and whisk for around 5 minutes on high until the mixture has cooled to room temperature.
Spread or pipe the meringue on top of the lemon filling, using a spatula or a spoon to shape the meringue. Either use a kitchen blowtorch to brown the meringue or place it under a hot oven grill/broiler for 2-3 minutes until browned.
Chill the Lemon Meringue Pie for at least 3 hours before cutting to ensure it is set.

Notes

To make Italian meringue you will need to measure the temperature of the sugar syrup as it needs to reach the 'soft ball' stage of around 116°C / 240°F. The old fashioned way of testing this is to drop a small amount of the syrup into very cold water, it should form a ball that does not hold in shape when gently pressed.

If the Italian Meringue seems like a bit too much of a fuss for you, you can simply beat the egg whites until firm, then add the sugar 1 tablespoon at a time until it is all used up. You'll need to bake the meringue topped pie for 20 minutes or so in the oven at 180°C / 350°F / Gas 4 until the topping is crisp and lightly browned.