Three Cheese, Spinach and Ham Filling

Ingredients:

Preheat a pan over medium heat, add the oil and sauté the onion until it is transparent, let cool

In a bowl beat the eggs with pepper, add the onion, spinach, and ricotta, mix well
Then add the Parmesan and Italian cheese and ham, mix well all the ingredients
Refrigerate the filling for a day so that the flavors are integrated