Grape and brown sugar galette

1. Put both the flours in a food processor with the salt and 20g sugar. Add the butter and pulse until it resembles coarse breadcrumbs. (If you don’t have a food processor, rub the butter into the dry ingredients with your fingertips.) Whisk the egg yolk with 3 tbsp cold water, pour it into the food processor and pulse until the dough starts to come together. Turn it out onto a lightly floured surface, bring it together with your hands – adding a little cold water if it feels dry – and mould it into a ball. Flatten into a disc and wrap in baking parchment or foil. Chill for at least 2 hours. 

2. Take the pastry out of the fridge and set aside for about 15 minutes before rolling. Preheat the oven to 200˚C, gas mark 6. In a large mixing bowl, whisk together the cornflour and jam; stir in the grapes. Roll out the pastry on a large piece of baking parchment into a circle 33-34cm in diameter. Transfer to a baking tray, keeping the paper underneath, and pile the grapes in the centre of the pastry, leaving a 6cm border. Fold the pastry inwards over the edges of the grapes. Sprinkle over the remaining 40g sugar. Lightly whisk the egg white and brush over the pastry border. Sprinkle the almonds all over the pastry, then put the galette in the oven. Bake for 25-30 minutes, until the pastry is golden all over. Leave the galette to rest for 30 minutes before serving with a drizzle of double cream, if liked.