Method

• 1.
  Place the butter, flour and a pinch of salt in a food processor and pulse to combine. Add the sour cream and pulse until the mixture comes together in a smooth ball. Enclose in plastic wrap and chill in the fridge for 30 minutes.

• 2.
  Meanwhile, preheat oven to 180°C and line a large baking tray with baking paper.
• 3.
  Place rhubarb, strawberries, caster sugar, custard powder, lemon zest and vanilla pod and seeds in a bowl and stir to combine. Set aside.
• 4.
  Roll out the pastry on a lightly floured surface into a 35cm circle. Carefully transfer to the baking tray and scoop the fruit mixture into the centre of the pastry, leaving a 6cm border. Fold over the pastry edge to form a 3cm crust, pressing down lightly with your fingers to seal. Brush the pastry with the egg yolk and scatter with almonds. Bake for 45-60 minutes until pastry is golden and cooked through, and juices are starting to run from the fruit.
• 5.
  Meanwhile, for the rose cream, place mascarpone, icing sugar and rosewater in a bowl and stir to combine. Cover and chill until ready to serve.
• 6.
  Allow galette to cool slightly, then dust pastry crust with icing sugar. Cut into slices and serve with rose cream.