Ingredients:

  • 225g (8 oz, 1 cup) unsalted butter, cold and cubed
  • 55g (2 oz, 1/4 cup) icing sugar, plus extra for dusting
  • 300g (10.5 oz, 2 1/2 cups) all-purpose flour
  • Pinch of salt
  • 200g (7 oz, 1 cup) granulated sugar
  • 4 large eggs
  • 175ml (6 fl oz, ¾ cup) fresh lemon juice (from about 4-5 lemons)
  • Zest of 2 lemons
  • 115g (4 oz, ½ cup) unsalted butter, cubed
  • 1 tbsp cornstarch
  • Icing sugar

Instructions:

  1. Combine flour, icing sugar, and salt in a bowl.
  2. Rub in the cold butter until the mixture resembles breadcrumbs.
  3. Press the mixture firmly into the prepared baking pan lined with parchment paper.
  4. Prick the base all over with a fork.
  5. Chill in the fridge for 1 hour.
  6. Preheat oven to 350°F (175°C).
  7. Bake the chilled base for 15-20 minutes, or until lightly golden.
  8. Remove from oven and let cool slightly.
  9. In a saucepan, whisk together sugar, eggs, and cornstarch until smooth.
  10. Add lemon juice, lemon zest, and butter.
  11. Cook over medium-low heat, whisking constantly, until the mixture thickens enough to coat the back of a spoon (approx. 8-10 minutes).
  12. Remove from heat and strain through a fine-mesh sieve to remove any lumps.
  13. Pour the lemon curd filling evenly over the baked shortbread base.
  14. Bake for another 15-20 minutes, or until the filling is set but still has a slight wobble.
  15. Let cool completely in the pan. Chill in the fridge for at least 2 hours before cutting.
  16. Dust with icing sugar before slicing into squares and enjoy your a lemon slice.