Mixed Berry Turnovers

Instructions

1. Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.
2. In a medium saucepan, combine mixed berries, granulated sugar, lemon zest and juice, vanilla extract, and fine sea salt. Cook over medium heat, stirring occasionally, until the mixture starts to bubble and the berries begin to break down, about 5 minutes.
3. In a small bowl, whisk cornstarch with 1 tablespoon cold water until smooth. Stir this slurry into the berry mixture. Continue cooking and stirring for 1-2 minutes until thickened. Remove from heat and let cool to room temperature, about 15 minutes.
4. On a lightly floured surface, roll out the puff pastry to about 12x12 inches (30x30 cm). Cut into 8 equal squares.
5. Spoon about 2 tablespoons of the cooled berry filling onto the center of each square, leaving a border around the edges.
6. Lightly brush the edges of each square with cold water. Fold each square diagonally in half to form triangles. Press the edges firmly with a fork to seal.
7. Transfer the turnovers to the prepared baking sheet. Beat the egg with water to make the egg wash; brush it evenly over the turnovers. Sprinkle with coarse sugar.
8. Chill the turnovers in the refrigerator for 15 minutes to help pastry hold its shape during baking.
9. Bake for 20-25 minutes until golden brown and puffed. Rotate the pan halfway through baking for even color.
10. Remove from oven; let cool on the baking sheet for 10 minutes before serving.