Hazırlanışı
1Wash the Starchy potatoes thoroughly and boil them in their skins in a large pot of salted water until very tender, about 30-40 minutes depending on size. Drain the Starchy potatoes and allow them to cool slightly, then peel them while still warm.
2Pass the peeled Starchy potatoes through a potato ricer or mash them very finely with a fork until no lumps remain. Transfer the mashed Starchy potatoes to a large bowl.
3Finely grate the Parmigiano-Reggiano and Pecorino Romano. Chop the Fresh flat-leaf parsley very finely. Cut the Low-moisture mozzarella into small cubes, about 0.5 cm.