Heat the oven to 400F.

On a lightly floured surface, roll out the puff pastry sheets to ⅛” thick rectangle. Cut each sheet into 6 triangles.

Place a few pieces of ham and cheese onto each triangle, keeping the ham and cheese away from the edge of the pastry. Roll each triangle into a croissant, starting with the narrow, non pointed edge of the pastry. Roll somewhat tightly. When you approach the pointed end, pull the tip gently to stretch and pull the end around the croissant, finishing with the tip tucking underneath the croissant. Pull each of the remaining tips of the pastry from the sides, stretching slightly, and tucking under the croissant as well. This will help keep most of the cheese from leaking out of the pastry, though some leakage is normal! Place croissants on a parchment lined baking sheet.

In a small bowl, beat the egg with 2 tsp water for 1 minute until well combined and slightly lighter in color. Use a pastry brush to paint the tops of the croissants with the egg wash, and sprinkle with everything bagel seasoning if using.

Bake for 30-35 minutes on the center rack, or until crisp and golden. Enjoy fresh or freeze and reheat at 350 for 12 minutes.