Easy Cheese Borekas

Preheat the oven to 350 F / 180 C. Line a baking sheet with parchment paper. In a bowl, mix the egg, cheese, parsley, garlic salt, and pepper. Using a sharp knife, cut the puff pastry into 5-inch squares. Place a heaping tablespoon of cheese filling in each square. Dampen the edges of the squares with water, and fold in half diagonally to form triangular pastries. Pinch the edges together to seal the filling inside. Brush the tops of the bourekas with beaten egg and sprinkle with sesame seeds. Bake in the preheated oven for 30 minutes, or until the pastries are puffed and golden, and the filling is cooked through. Serve immediately.