01 -
Remove puff pastry sheets from packaging and let thaw until pliable.
02 -
Preheat oven to 425°F and line a large baking sheet with parchment paper.
03 -
Roll out each puff pastry sheet slightly if needed and slice each into six rectangles using a sharp knife or pizza cutter.
04 -
Brush edges of each pastry rectangle with whisked egg, spread Dijon mustard in the center, then place one slice of Gruyère cheese and a folded slice of ham onto the mustard.
05 -
Lift one corner of the pastry towards the center, fold the opposite corner over to enclose the filling, and press edges gently to seal.
06 -
Transfer pastries to the lined baking sheet, brush tops with remaining egg wash, and sprinkle everything bagel seasoning if desired.
07 -
Bake in preheated oven for 18 to 22 minutes until golden, puffed, and cheese is melted.
08 -
Remove from oven and allow to cool briefly before serving warm.