Wash and chop the spinach, removing thick stems. In a pan, heat olive oil over low heat, add garlic, and sauté for a minute. Add spinach and cook for about 10 minutes until wilted. Remove excess moisture by squeezing it well.
In a bowl, mix ricotta, chopped spinach, Parmesan, nutmeg, egg, and salt until well combined.
Roll out the puff pastry and place it in a pie dish. Pour the filling inside and spread evenly. Fold the edges over the filling to create a decorative crust.
Brush the pastry edges with egg yolk for a golden finish. Bake in a preheated oven at 360°F (180°C) for 30 minutes, or until the crust is golden and crisp.
Let the pie cool for a few minutes before slicing. Serve warm and enjoy!
