1. Heat olive oil or butter in a skillet over medium heat and cook onion until translucent, then add garlic and sauté until fragrant.

2. Add spinach and cook until wilted or warmed through, then remove from heat and let cool.

3. In a bowl, mix ricotta cheese, cooked spinach mixture, grated Parmesan, one egg, nutmeg, salt, and pepper until smooth.

4. Preheat oven to 200C (400F) and line a baking tray with parchment paper.

5. Roll out puff pastry sheets and cut each into 3×3 inch squares.

6. Place a spoonful of filling in the center of each square, fold into triangles, and seal edges with a fork.

7. Brush each pastry with beaten egg and pierce the tops to allow steam to escape.

8. Bake for 18-22 minutes until puffed and golden brown.

9. Cool slightly on a wire rack and serve warm or at room temperature.