Preheat the oven to 180°C.
Line a baking sheet with parchment paper.
In a bowl, place the berries pieces with the sugar, corn flour. Toss to coat the fruits once or twice.
On a lightly floured work surface, roll the pastry into an approximate circle or square about 20cm in diameter or size and 2mm thick.
Pour the fruit mixture over the pastry.
Tidy the pastry edges over the fruits if needed and brush the edges with egg wash.
Sprinkle the pistachios over the tart.
Place in the oven for 25 - 35 minutes until golden brown and the fruits are bubbling.
Remove from the oven, serve warm or at room temperature with a dusting of icing sugar.
