Thaw puff pastry sheets in the refrigerator for 3 to 4 hours, or at room temperature for 20 to 40 minutes, according to the manufacturer’s directions.

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

Sprinkle a work surface with 1 tablespoon flour and roll out 1 puff pastry sheet into a 12x12-inch square. Cut into 9 equal squares and place them on the prepared pan.

Leaving a 1/2-inch border, brush the center of each square with 1 teaspoon chipotle mayonnaise, fold roast beef slices to fit within the border, and top with Cheddar cheese pieces.

Roll out the second puff pastry sheet in the same manner, cut into 9 squares, and prepare an egg wash by mixing the egg with 1 tablespoon of water.

Cover each filling stack with a square of the second pastry layer, crimp edges with a fork, brush with egg wash, and sprinkle with Everything Bagel seasoning.