In a food processor pulse together flour, sugar, and salt. Then slowly add the butter pulsing until a coarse meal forms.

Whisk together the egg yolk and ice water and then slowly add this mixture to the food processor pulsing until a dough ball forms. Chill in refrigerator for at least 1 hour.

Once dough is chilled, roll out and fit into a tart tin. Place in freezer for 30 minutes.

Preheat oven to 350F (176C). Place a sheet of parchment paper on top of tart, fill with baking beads (or rice or beans) bake for 35 minutes until baked and golden brown. Set aside to cool.

For filling. In a large bowl, mix together egg yolks, salt and cornstarch and set aside. In a saucepan heat water and sugar until dissolved. Slowly pour sugar water into egg mixture until combined. Then transfer mixture back into saucepan, cooking on medium flame and stirring until thickened. Whisk in butter and lemon juice. Transfer to pie shell and refrigerate.

For meringue, place sugar and water in a saucepan over high heat. Bring to a boil, reduce heat to low and cook for 5 mins until syrupy. Place egg whites in the bowl of an electric mixer, add cream of tartar. Whip on high until soft peaks form, while motor is running slowly add the hot sugar syrup whisking all the while until stiff and glossy.

Dollop the meringue over the pie, creating decorative swoops and swirls. Place pie under the broiler for 1 minute or until golden brown. Or brown with a kitchen torch.

Refrigerate until ready to serve.