Wash the spinach well. Chop the onion and brown it in a pan with a little extra virgin olive oil. Add the spinach and let it wilt. Season with salt and pepper to taste. Chill the spinach in a blast chiller until it is at room temperature.
Meanwhile, prepare the base of the pie. Pour the flour, all the water, extra virgin olive oil and salt into a bowl. Knead until a homogeneous dough is obtained. Shape into a ball, cover with cling film and leave to rest for at least 30 minutes at room temperature.
In a bowl, mix the spinach with 1 egg, the ricotta cheese, 70 g Parmesan cheese and the nutmeg. Mix well.
Roll out ¾ of the dough fairly thin and place in a 24 cm mould sprinkled with oil. Pour in the spinach mixture, form 4 basins and place 1 egg in each. Sprinkle with the remaining Parmesan cheese and cover with the remaining piece of dough, also rolled out thinly.
Brush with extra virgin olive oil and bake for at least 50 minutes, until the dough is golden brown.