Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.

Roll out the thawed puff pastry on a lightly floured surface to about ⅛ inch thickness.

Cut the rolled-out pastry into rectangles, approximately 3 inches by 5 inches, aiming for about 12-16 rectangles.

Spread a thin layer of Dijon mustard over one half of each pastry rectangle.

Layer a slice of deli ham and a slice or sprinkle of cheese over the mustard.

If using, sprinkle fresh parsley over the cheese layer.

Season the filling lightly with salt and pepper.

Fold the other half of the pastry over the filling, pressing down the edges to seal.

Place the assembled sticks on the baking sheet, spaced apart, to allow for puffing up.

Brush the tops of the sticks with the beaten egg for a shiny finish.

Bake in the preheated oven for 15-20 minutes until they are golden brown.

Allow to cool slightly on the baking sheet, then serve warm.