Making Cheese and Spinach Puff Pastry Pockets is straightforward when you follow these simple steps:

1. Preheat the Oven: Begin by preheating your oven to 400°F (200°C). Prepare a baking sheet lined with parchment paper.

2. Sauté Spinach: In a skillet, heat the olive oil over medium heat. Add the minced garlic, cooking it until fragrant (about 1 minute), then add the chopped spinach. Sauté for 2-3 minutes until wilted. Remove from heat and let cool.

3. Make Filling: In a bowl, mix the ricotta cheese, mozzarella cheese, Parmesan cheese, and sautéed spinach together. Season with salt, pepper, and nutmeg if desired.

4. Prepare Puff Pastry: Roll out the thawed puff pastry on a lightly floured surface. Cut the pastry into squares, about 4-5 inches per side.

5. Fill the Pastry: Place a spoonful of the cheese and spinach mixture in the center of each pastry square. Be careful not to overfill!

6. Seal the Pockets: Fold the pastry over to create a triangle shape. Seal the edges by pressing down with a fork. Make sure there are no openings for the filling to escape.

7. Egg Wash: Brush the tops of each pastry pocket with the beaten egg to achieve a golden color when baking.

8. Bake: Place the filled pastries on the prepared baking sheet. Bake in the preheated oven for 20-25 minutes, or until they are golden brown and puffed up.

9. Cool: Once baked, remove the pockets from the oven and let them cool for about 5-10 minutes before serving.