Thaw puff pastry sheets on the counter or overnight in the fridge.
Unroll the puff pastry onto a piece of parchment paper and use a rolling pin to slightly thin out both sheets.
In a bowl, combine all ingredients for the cheese filling. If the mixture is watery, add 1-2 tbsp. of flour. Make sure you're not adding any extra water from the cheeses.
Place one sheet of puff pastry on parchment paper and use a 1.5-inch mini scooper to add the cheese filling in a 4X6 grid, making 24 squares.
Place the second sheet of dough on top and gently press around the fillings. Use a pizza cutter to slice through the dough, creating squares.
Slide the entire sheet onto a baking sheet.
Beat an egg for the egg wash. In a small bowl, combine za'atar and sesame seeds.
Brush the egg wash over the pastry and sprinkle the za'atar and sesame seed mixture generously.
Bake in a preheated oven at 375°F for about 45 minutes
Enjoy the cheese-filled puff pastry pockets hot, paired with vegetables or a chopped salad.
