Preheat your oven to 200°C (390°F) and line a baking sheet with parchment paper to prevent sticking.
Thaw the puff pastry sheets in the fridge for about 30 minutes, keeping them cold for easy handling.
Lightly dust your work surface with flour and roll out each sheet to about 2mm thickness, smoothing the edges for a uniform look.
Use a sharp knife or pizza cutter to cut the pastry into approximately 2-inch squares, then transfer them to the prepared baking sheet, spacing them about 1 inch apart.
Chill the cut pastry squares in the fridge for 10 minutes to help keep layers crisp during baking.
While they chill, beat the egg with water to create an egg wash, then set aside.
Remove the pastry from the fridge and lightly brush the edges of each square with the egg wash to give a shiny, golden finish.
Top each square with about a teaspoon of grated cheese and sprinkle with chopped herbs, pressing down gently so they stay in place during baking.
Bake in the preheated oven for 12-15 minutes, until the bites are puffed, golden, and the cheese is bubbling.
Once baked, remove from the oven and sprinkle with a pinch of flaky sea salt for a finishing touch. Let them rest for 5 minutes to set before serving.
Enjoy these flaky, cheesy bites warm or at room temperature, perfect for sharing and spontaneous snacking.
