Squeeze the wilted spinach with your hands to get rid of as much liquid as possible.
Sauté the garlic in the butter. Add the wilted spinach and sauté for 2 minutes. Season with salt and pepper and keep aside to cool down.
Filling
Now cut the cooled down spinach finely with a knife and put it in a mixer with the ricotta. Blend until combined.
Put the spinach and ricotta mix in a bowl, add the egg, grated Parmigiano Reggiano, nutmeg, salt and pepper and mix until well combined. Refrigerate until ready to use.
Assembling
Put the puff pastry in a 20x20 cm – 8x8 inch oven dish lined with baking paper. Keep a piece of puff pastry aside so that it can be cut into strips to be put on the top as decoration.
Pour the filling onto the puff pastry and flatten it out with a spoon.
Gently press the sides of the pastry with a fork to create a border and add the strips of pastry on the top to decorate the quiche. Brush the pastry with egg wash (optional).
Bake in a pre-heated fan forced oven at 200°C – 390°F for 20-25 minutes or until golden brown.
Before slicing it, let the quiche cool down. This will prevent it from crumbling. Serve at room temperature with a simple green salad on the side.