11/4 cups plain flour
1/4 cup caster sugar
Finely grated zest of 1 lemon
1/4 tsp sea-salt flakes
125g unsalted butter, cubed and chilled, plus extra, for greasing
1 free-range egg yolk
11/2 Tbsp sour cream (or ice water or milk)
Dried orange, blood orange and lime slices, to serve (see Cook’s tip)
Blood Orange Curd
1/2 cup blood orange juice
Finely grated zest of 2 blood oranges
125g unsalted butter, chopped
1 cup caster sugar
1 Tbsp cornflour
3 free-range eggs
3 free-range egg yolks
4 free-range egg whites
1 cup caster sugar
1 tsp vanilla extract
Put flour, sugar, lemon zest and salt in bowl of a food processor and pulse to combine. Add butter and pulse until mixture resembles breadcrumbs.
Add egg yolk and sour cream and pulse a few more times until dough starts to clump together.
Turn dough out onto a clean surface and use your hands to gently bring together until fully combined. Cover with plastic wrap, flatten into a disc and refrigerate for 1 hour.
Preheat oven to 170°C fan-forced (190°C conventional) .Grease a 34 x 12cm loose-based tart tin.
On a floured surface, roll dough between 2 sheets of baking paper to a rough 38 x 16cm rectangle and gently ease into prepared tin. Freeze for 20 minutes.
Prick base of tart shell several times with a fork, trim excess from edges and cover with a layer of baking paper. Fill with dried beans, rice or pie weights and blind bake for 20 minutes. Remove weighted baking paper and bake for 10 minutes, until golden.
Meanwhile, to make curd, combine juice, zest and butter in a small saucepan on low and bring to a simmer. In a large heatproof bowl, whisk sugar and cornflour together, then add eggs and yolks. Very slowly pour butter mixture into egg mixture, whisking constantly. Return mixture to a large clean saucepan and cook on low heat, whisking constantly, for 8 minutes, or until mixture thickens and coats the back of a spoon. Strain into a bowl.
For meringue, in the large bowl of a stand mixer beat egg whites until foamy. Gradually add sugar, beating between additions until stiff peaks form and sugar has dissolved. Add vanilla and beat until combined.
Dollop curd into tart shell, then spoon meringue onto tart using back of spoon to create decorative swirls. Bake for 10 minutes, or until meringue is golden brown on top (or use a blowtorch to colour). Cool tart fully. Remove from tin, decorate with dried citrus slices and serve.