You can have the tart case and syrup ready to go the day before
and fill it at the last minute. Any type of berry would work well
in this recipe.
3punnets blueberries (about 375gm)Sweet pastry170 gmunsalted butter, at room temperature, coarsely chopped40 gmpure icing sugar1small egg yolk from a 55gm egg240 gmplain flour, sievedBlueberry syrup150 gmfrozen blueberries2 pieceslemon rind, removed with a peeler150 gmcaster sugarCrème fraîche filling250 gm eachcrème fraîche and mascarpone80 ml(1/3 cup) thickened cream1vanilla bean, split and seeds scraped1 tspvanilla extract45 gmpure icing sugar, sieved
For blueberry syrup, combine ingredients in a heatproof bowl, cover with foil, place over a saucepan of simmering water and cook until syrupy and berries are deep purple (2 hours). Strain through a muslin-lined sieve (do not press solids), discard solids and refrigerate syrup until required.
Meanwhile, for sweet pastry, beat butter and sugar in an electric mixer until pale, add yolk and mix until just combined. Add flour and 20ml water, mix until dough just comes together. Turn out onto a lightly floured surface and shape into a disc, then wrap in plastic wrap and refrigerate until firm (1 hour). Roll pastry to a 30cm-diameter round and line a buttered and floured 24cm-diameter fluted tart tin. Refrigerate until chilled and rested (1 hour). Preheat oven to 180C. Blind-bake tart until golden around edges (25-30 minutes), remove paper and weights, cook until golden and cooked through (15-20 minutes). Cool, then carefully transfer to a serving plate and set aside.
For crème fraîche filling, whisk all ingredients in a bowl until medium peaks form (do not overbeat as mixture may split), spoon into tart case and spread to fill.
To serve, scatter fresh blueberries over tart and drizzle with blueberry syrup to taste.