Grate the potatoes and squeeze out excess moisture using a clean kitchen towel.
In a bowl, mix the grated potatoes with cornstarch, salt, black pepper, and chopped parsley.
Take a portion of the mixture, flatten it in your hands, place some grated mozzarella in the center, and cover with more potato mixture to form a patty.
Heat olive oil in a pan over medium heat. Fry the fritters for 3-4 minutes per side until golden brown and crispy.
Remove from the pan, let them rest for a minute, and serve warm with your favorite dipping sauce.