For the spinach pie, line the pan with puff pastry and pre-bake briefly in the oven (approx. 180 ºC).
Wash fresh spinach leaves, steam them in a saucepan together with the chopped tomato (add some water if necessary, usually the water from washing is enough).
Instead of the fresh tomato, you can also chop some dried tomatoes and add them. Season with a little salt. Pour the spinach mixture into the mold.
Divide the mozzarella into pieces by hand and place in the dish as well. Bake in the oven until mozzarella melts.