Method

• 1.
  For the pastry, combine vinegar and 1/4 cup (60ml) iced water in a jug. Place flour in a large bowl with sugar, vanilla seeds and a pinch of salt flakes. Add butter and toss to coat, then rub into flour mixture, leaving some larger pieces (this will make the pastry nice and flaky).
• 2.
  Stir in sour cream, then gradually add vinegar mixture, bringing the dough together with your hands (don’t add extra water – the dough will be quite shaggy, but will come together once chilled). Turn out onto a lightly floured work surface and gently knead.
• 3.
  Enclose in plastic wrap and chill for at least 2 hours before using.
• 4.
  For the galette, grease a baking tray and line with baking paper. Roll out pastry on a lightly floured work surface to form a 3mm-thick, 35cm round. Transfer to prepared tray. Set aside.
• 5.
  Place 1 2/3 cups (250g) blueberries, caster sugar, orange zest and juice, and 2 tbs gin in a saucepan over medium heat. Cook, stirring occasionally, for 10 minutes or until blueberries have broken down. Remove 1/3 cup (80ml) liquid and place in a small bowl. Add cornflour and stir until smooth.

• 6.
  Add mixture to saucepan and cook for 2-3 minutes or until thickened slightly. Remove from heat and set aside to cool. When at room temperature, fold through remaining 125g blueberries and 85ml gin.
• 7.
  Preheat oven to 220°C.
• 8.
  Scatter hazelnuts over pastry, leaving a 12cm border. Spoon blueberry mixture over nuts. Fold over pastry edges to create a 6cm border, then fold over border to partially enclose filling. Brush pastry with egg, then sprinkle with demerara sugar.
• 9.
  Bake for 25 minutes, then reduce oven to 180°C and bake for a further 20 minutes or until pastry is golden. Cut into pieces and serve with cream.