Steps
- Mix 2 cups of all-purpose flour, ¼ teaspoon of salt, ¼ cup of softened unsalted butter, and ½ cup plus 2 tablespoons of water. Knead for 3-5 minutes, until soft.
- Roll to a rectangle three times as long as it is wide and ¼in / 5mm thick. Spread with half of 3 tablespoons of softened unsalted butter and sprinkle with half of 2 tablespoons of cornstarch.
- Fold the bottom third up and the top third down; turn a quarter-turn and roll out again. Repeat with the remaining butter and cornstarch, fold, and refrigerate for 40 minutes.
- Preheat the oven to 400°F / 205°C. Cut 4 slices of mozzarella and 140g of quince paste into 1in / 2.5cm pieces.
- Roll the pastry on a floured surface to a 5 × 24in / 13 × 61cm rectangle. Cut 4in / 10cm rounds, stacking, chilling, and re-rolling scraps.
- Divide the quince and cheese among the rounds. Fold over, pinch shut, and crimp with a fork; arrange on a baking sheet.
- Brush with 1 beaten egg and sprinkle with sugar. Bake for 25 minutes, until golden brown.