WHAT YOU NEED

Shortbread

1. Preheat the oven to 180°C. Lightly grease and line the base and sides of a 20x30cm slab tin with baking paper.
2. In a bowl, sift together the flour and salt, and set aside. Beat the butter, sugar and vanilla until pale and creamy. Add the sifted dry ingredients and bring together until a dough has formed.
3. Press two-thirds of the dough into the prepared tin, reserving the remaining one-third for the topping. Flatten the reserved dough, wrap in plastic wrap, and chill in the fridge while the base is baking.
4. Bake the base for 25 minutes or until golden brown. Remove from the oven and let cool in the tin.
5. Spread the cooled shortbread base with the lemon curd and evenly crumble or grate the chilled portion of dough over the lemon curd. Return to the oven and bake for a further 30 minutes or until golden brown. Cool in the tin.
6. Using a sharp knife, cut into rectangles approximately 5×7.5cm to make 16 pieces.

Lemon Curd

1. In a large heat-proof bowl, whisk together the lemon juice, whole eggs and egg yolks, caster sugar and salt until well combined. Place over a large saucepan of simmering water, and make sure the base of the bowl does not touch the water.
2. Hand-whisk for approximately 10-15 minutes until the mixture becomes very thick and reaches 82°C on a sugar thermometer. Remove the bowl from the saucepan.
3. Add the butter a little at a time, whisking after each addition and making sure the butter is fully incorporated before adding more.
4. Lemon curd should be pale yellow and thick.