Method

• 1.
  Process flour, icing sugar, 125g butter and a pinch of salt in a food processor until the mixture resembles fine breadcrumbs. Add 1 yolk and 2-3 tablespoons iced water, and process until mixture comes together in a smooth ball. Enclose in plastic wrap and chill for 30 minutes.
• 2.
  Meanwhile, place cornflour in a bowl with 1 cup (250ml) water and stir until smooth. Place in a pan with lemon juice and 1/2 cup (110g) caster sugar, and stir over low heat for 7-8 minutes until thickened. Remove from heat and add remaining yolks, one at a time, combining well with a wooden spoon. Stir in limoncello and remaining 65g butter, then cover surface with a piece of baking paper (to prevent a skin from forming) and cool.
• 3.
  Lightly grease eight 8cm-diameter loose-bottomed tart pans. Roll out pastry on a lightly floured surface until 3mm thick. Line each pan with pastry, trim edges to fit and chill for 10 minutes.

• 4.
  Preheat oven to 180°C. Line tarts with baking paper and fill with pastry weights or uncooked rice. Blind-bake for 10 minutes, then remove weights and paper and bake for 5 minutes. Spread filling into the pastry cases and chill for 1 hour.
• 5.
  Preheat oven to 200°C. Using electric beaters, beat eggwhites until soft peaks form. Gradually add remaining sugar and beat until glossy and firm. Pipe or spoon onto tarts and bake for 5-6 minutes until top is golden. Cool slightly before serving