Place shredded chicken in a large bowl. Add barbecue sauce, onion, garlic powder, black pepper, salt and parsley. Mix everything well until the chicken is evenly coated and smells delicious.

Add shredded cheddar cheese to the barbecue chicken mixture. Stir gently until the cheese is evenly distributed. Avoid adding too much sauce, as excess moisture can make the pastry difficult to crisp.

Place the thawed puff pastry on a lightly floured surface. Roll it gently if needed. Keep the pastry cold while working, as chilled pastry creates better flaky layers during baking.

Cut the pastry into eight equal rectangles or squares. Try to keep the pieces similar in size. This helps them bake evenly and makes serving easier for everyone at the table.

Place a spoonful of barbecue chicken filling in the center of each pastry piece. Leave space around the edges. Too much filling can prevent the pastry from sealing properly.

Fold each pastry over the filling to create a pocket. Press the edges firmly with your fingers. Then use a fork to seal the edges and create a simple decorative pattern.

Whisk the egg with one tablespoon of water in a small bowl. Brush the tops of each pastry lightly. The egg wash helps create a beautiful golden surface while baking.

Sprinkle sesame seeds over the pastries if desired. They add a light crunch and make the pastries look extra inviting. You can skip them if you prefer a simple golden finish.

Place the pastries on a parchment-lined baking sheet. Bake at 400°F (200°C) for about 20 to 25 minutes. They should become puffed, crisp, and deeply golden on top.

Remove the pastries from the oven and let them cool for several minutes. The filling will be very hot inside. Serve warm with extra barbecue sauce for dipping.