Potato cake with mushrooms. Simple and delicious!

Ingredients:
Potatoes - 3 pcs. (Fry potatoes until golden brown, 7 - 10 minutes).
Mushrooms - 300 g.
Onion - 1 pc.
Mozzarella – 200g (or any other cheese)
Salt
Black pepper
puff pastry
Potatoes - 1-2 pcs.
Shape - 22 - 24 cm.
Bake for 35 minutes at 180°C – 190°C.