Method

• 1.
  Slice the lemons as thinly as possible and combine in a non-reactive bowl with the sugar. Cover and set aside overnight at room temperature.
• 2.
  For the pastry, place our, sugar and a pinch of salt in a bowl and stir to combine. Add the butter and toss to coat, then rub in the butter with you hands, leaving some large clumps in the dough.
• 3.
  Combine vinegar, 1 egg and 100ml iced water in a jug. In 3 batches, add to the our mixture, kneading gently to combine. Turn dough out onto a clean work surface and knead until a rough pastry forms.
• 4.
  Divide into two pieces and enclose each piece in plastic wrap. Chill for 3 hours or overnight.
• 5.
  The next day, remove pastry from the fridge and set aside for 10 minutes to soften slightly. Roll out one piece of pastry on a lightly oured work surface until 3mm thick, then use to line a 24cm x 3cm uted loose-bottomed tart pan.
• 6.
  Chill until needed. Roll out second piece of pastry until 3mm thick and place on a baking tray. Chill until needed.
• 7.
  Preheat oven to 200°C. Combine lemon mixture, beaten egg and egg yolk, our and a pinch of salt in a bowl.
• 8.
  Pour into the pastry case, spreading lemons evenly over the pastry. Place second sheet of pastry over the top and press onto the edges of the base.
• 9.
  Fold the overhanging edge over onto itself to create a thick border, then using your thumb and fore finger, pinch to form a fluted rim.
• 10.
  Beat remaining egg in a bowl with 1 tbs cold water. Make an incision in the centre of the pie, then brush the top of the pie with eggwash and scatter with extra sugar.
• 11.
  Place on a baking tray and bake for 40-50 minutes until pastry is golden and cooked through. Remove from oven and set aside to rest for 2 hours. Scatter with more sugar, then, using a blowtorch, caramelise the top of the pie. Serve pie slightly warm with creme fraiche or cream.