To make the pastry, sift the flour and icing sugar together into a bowl. Rub the butter into the dry ingredients with your fingertips until the mixture resembles breadcrumbs. Add the whole egg and yolk and stir until the pastry comes together.
Knead the pastry lightly on a floured work surface. Shape into a ball, wrap in cling film and leave to rest in the refrigerator for 1 hour.
Lightly butter a 26cm (10½in) tart tin. Roll out the pastry thinly on a lightly floured work surface and use the pastry to line the tin. Trim the edges and leave to rest again in the refrigerator for 1 hour.
Preheat the oven to Gas 4, 180°C, fan160°C. Cover the pastry with a circle of baking paper and weigh it down with dry beans or rice. Bake for 20 minutes. Take the tart case out of the oven and remove the baking paper and beans. Return the tart case to the oven for another 10 minutes.
To make the filling, rinse the blueberries and mix them with the sugar. Remove the pastry case from the oven and increase the oven temperature to Gas 6, 200°C, fan180°C. Pour the blueberries into the pastry case and return to the oven for 20 minutes.
Remove the tart from the oven and let it cool for 10 minutes before serving with crème fraîche.
Recipe from The Scandinavian Cookbook, by Trina Hahnemann, published by Quadrille Publishing, £20. Click here to buy the book.
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