Preheat your oven to 190°C (375°F) so it reaches the correct temperature before baking—this is key for achieving that perfectly flaky, golden puff pastry texture. Line a baking tray with parchment paper to prevent sticking and to ensure the bottoms cook evenly without burning.

In a medium to large mixing bowl, add the cooked shredded chicken, Greek yogurt, and shredded cheese. Gently mix everything together until the filling becomes creamy and well combined. Make sure the mixture isn’t too wet—if it feels overly soft, you can add a little extra cheese to balance it. Avoid overmixing, as this can break down the texture of the chicken.

Place your puff pastry sheet on a clean, lightly floured surface and gently roll it out just enough to smooth any folds and slightly enlarge it. Using a sharp knife or pizza cutter, cut the pastry into equal-sized squares so each parcel cooks evenly and looks consistent when baked.

Take a spoonful of the prepared filling and place it in the center of each pastry square. Be careful not to overfill—keeping the filling moderate ensures the parcels seal properly and prevents the mixture from leaking out during baking.

Fold each pastry square over the filling to form a parcel shape (triangle or rectangle works well), then press the edges firmly together using your fingers. For a tighter seal and a decorative touch, use a fork to crimp the edges—this helps lock in the filling while baking.

In a small bowl, beat the egg and use a brush or spoon to lightly coat the top of each parcel. This egg wash gives the pastries a beautiful golden shine and helps create a slightly crisp, bakery-style finish.

Arrange the prepared parcels on the lined baking tray, leaving a small gap between each one. This spacing allows hot air to circulate around them, helping the pastry puff up properly and bake evenly on all sides.

Place the tray in the preheated oven and bake for 18 to 22 minutes, or until the parcels are puffed, golden brown, and crisp on the outside. Keep an eye on them toward the end to avoid over-browning.

Once baked, remove the parcels from the oven and let them cool for a few minutes before serving. This resting time allows the filling to set slightly and prevents burning your mouth, while also keeping the texture perfectly flaky and enjoyable.