Ingredients:

  • 2 cups all-purpose flour, plus extra for dusting
  • 1/2 teaspoon fine sea salt
  • 7 oz (200 g) very cold unsalted butter, cut into 1/2-inch cubes
  • 5–7 tablespoons (75–100 ml) ice water
  • 2 tablespoons olive oil
  • 1 medium yellow onion, finely diced
  • 2 medium carrots, finely diced
  • 1 stalk celery, finely diced
  • 5 oz (140 g) button mushrooms, chopped small
  • 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried)
  • 1/2 teaspoon dried sage
  • 2 cups (100 g) packed spinach, chopped and squeezed dry
  • 4 oz (115 g) crumbled feta cheese
  • 2 tablespoons dried breadcrumbs (Panko preferred)
  • Black pepper and salt, to taste
  • 1 large egg, for egg wash
  • 1 teaspoon milk or water, mixed with egg
  • 1 tablespoon sesame seeds or poppy seeds (optional)

Instructions:

  1. In a large bowl, whisk together the flour and salt. Add the cold butter cubes. Using your fingers, rub the butter into the flour until large chunks (about the size of walnuts) still remain.
  2. Gradually add the ice water, mixing with a knife or fork until the dough just comes together into a shaggy mass. Do not overwork. Wrap tightly and chill in the refrigerator for 30 minutes.
  3. On a lightly floured surface, roll the chilled dough into a long rectangle (approx. 12x6 inches). Perform a 'letter fold': Fold the bottom third up, and the top third down, creating three layers. Turn the dough 90 degrees.
  4. Repeat the roll, fold, and turn process two more times (for a total of three folds). Wrap the dough and chill for 30 minutes after each set of folds. The final pastry must be well-rested before assembly.
  5. Heat olive oil in a skillet over medium heat. Add diced onion, carrot, and celery. Sauté for 8–10 minutes until softened.
  6. Add the mushrooms, thyme, and sage. Increase heat and cook until all liquid released by the mushrooms has completely evaporated. Removing this moisture is vital to prevent soggy pastry.
  7. Stir in the chopped spinach. Cook for 1–2 minutes until wilted, then immediately transfer the entire mixture to a bowl to cool completely.
  8. Once the filling is completely cool, stir in the crumbled feta cheese, breadcrumbs, salt, and pepper until the mixture holds together lightly.
  9. Preheat the oven to 400°F (200°C). Line baking sheets with parchment paper. Beat the egg with milk/water for the wash.
  10. Roll the final chilled pastry block into a large rectangle (approx. 18x12 inches), about 1/8 inch thick. Cut the rectangle into six equal pieces.
  11. Place an even amount of filling down the center of each pastry piece, leaving a 1-inch border. Brush the edges with egg wash.
  12. Fold the pastry over the filling and crimp the edges tightly using a fork to seal. Transfer rolls to the prepared baking sheets.
  13. Brush the tops generously with the remaining egg wash. Score the top of each roll 2–3 times for venting. Sprinkle with seeds, if using.
  14. Bake for 30–35 minutes, rotating the trays halfway through, until the pastry is deeply golden brown, puffed, and crisp. Cool on the tray for 10 minutes before serving.