Tasty puff pastry with ham and cheese and bechamel sauce

Ingredients:
For the puff pastry:
Puff pastry: 500 g
Mustard: 50 g
Ham: 200 g, thinly sliced ​​Cheese
: 200 g, grated or thinly sliced ​​(cheddar, Gruyère or Swiss)
Egg: 1, for brushing

For the béchamel sauce:
Butter: 30 g
Flour: 25 g
Milk: 300 ml
Nutmeg: 4 g
Black pepper: 5 g
Salt: 10 g
Parmesan: 30 g, grated
To garnish:
Pickled cucumbers: 40 g, finely chopped

Instructions: