- 500g plain flour
- 550g caster sugar
- 200g cold unsalted butter, finely diced
- 2 eggs
- 5 egg yolks
- finely-grated zest of four lemons
- 375ml lemon juice
- 750ml water
- 125g potato flour, sifted
- icing sugar, to serve.
1 Preheat oven to 180°C. Combine the flour and 150g caster sugar in the bowl of a food processor and pulse to combine. Add the butter and pulse until a coarse crumb forms. Add the eggs and 1 egg yolk, and continue pulsing until a dough forms. Flatten into a large rectangle, wrap well, then refrigerate for 1 hour.
2 Combine the remaining sugar with the remaining egg yolks, lemon juice, water and potato flour in a large bowl and whisk until smooth. Set aside for 15 minutes.
3 Pour the lemon mixture into a saucepan and set over a low heat. Cook gently, whisking constantly, until the mixture forms a smooth creamy texture. Set aside to cool completely.
4 Roll out half the pastry to 3mm thick and line into a lightly-greased 26cm tart tin. Fill with the cool cream, then roll out the remaining pastry to cover and drape on top, crimping the edges to seal. Bake for 45 minutes, until deep-golden, then set aside to cool completely. Dust with icing sugar to serve.