Directions:

• Step 1: Preheat the Oven - Begin by preheating your oven to 400°F (200°C).
• Step 2: Prepare the Filling - In a mixing bowl, combine the crumbled feta, grated kashkaval, ricotta cheese, and one large egg. Season with salt and pepper to taste. Mix well until all ingredients are thoroughly combined and creamy.
• Step 3: Roll Out the Puff Pastry - If using puff pastry that is not already rolled out, lightly flour your work surface and roll it out to about 1/8 inch thick.
• Step 4: Cut the Pastry - Using a sharp knife or pizza cutter, cut the rolled-out pastry into squares, approximately 4x4 inches.
• Step 5: Fill the Pastry - Place a tablespoon of the cheese filling in the center of each square. Be careful not to overfill.
• Step 6: Fold and Seal - Fold the pastry over the filling to create a triangle. Press the edges together to seal, and use a fork to crimp the edges.
• Step 7: Prepare for Baking - Line a baking sheet with parchment paper and place the bourekas on it. Brush with the egg yolk.
• Step 8: Bake - Bake in the preheated oven for 20-25 minutes or until golden brown and puffed.
• Step 9: Cool and Serve - Once baked, remove the bourekas from the oven and let them cool for a few minutes before serving.