Preheat the oven to 200°C (400°F).

Roll out the puff pastry on a lightly floured surface to smooth it out.

Cut the puff pastry into rectangles, about 10x5 cm each.

Spread a thin layer of Dijon mustard on each rectangle (if using).

Place a slice of ham and a generous amount of cheddar cheese on one half of each rectangle.

Fold the other half of the pastry over the filling and press the edges to seal.

Place the filled sticks on a baking sheet lined with parchment paper.

Brush the tops with beaten egg and sprinkle sesame seeds on top.

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

Remove from the oven and let cool slightly before serving.

Serve warm with your favorite dipping sauce.