Preheat oven to 200°C (390°F). Line a lightly greased 22cm pie tin with the pastry and trim the edges. Prick the base with a fork and line with baking paper and baking weights. Cook for 15 minutes, remove the paper and weights and cook for a further 10–15 minutes or until golden and crisp. Cool on a wire rack.
To make the curd, place the milk and sugar in a saucepan over medium heat and stir until the sugar is dissolved. Place the cornflour and extra milk in a small bowl and stir to combine. Pour the cornflour mixture into the milk mixture and stir to combine. Bring to the boil and then reduce the heat to low. Add the butter and whisk until melted and combined. Add the lemon juice, rind and egg yolks and cook, whisking, for 5 minutes or until thickened. Spoon the lemon mixture into the pastry case and refrigerate for 2 hours or until set.
To make the meringue, place the eggwhites in the bowl of an electric mixer and whisk until soft peaks form. Gradually add the sugar and white vinegar and beat until thick and glossy. Spoon the meringue on top of the curd and grill (broil) under a preheated hot grill for 1–2 minutes or until golden and cooked.