01 -
Heat the oven to 400°F (200°C). Line a large rimmed baking sheet with parchment paper and lightly grease the paper with cooking spray.
02 -
Grate the peeled potatoes on the large holes of a box grater. Working in batches, wrap the grated potato in a clean kitchen towel and wring tightly until almost no moisture comes out. The potato should feel nearly crumbly when properly squeezed.
03 -
In a large bowl, combine the squeezed potato, beaten eggs, 1 1/2 cups mozzarella, salt, pepper, and parsley. Stir until combined. Spread the mixture onto the prepared pan into an even rectangle about 12 by 10 inches and 1/4 inch thick, pressing flat with a spatula.
04 -
Bake for 20 to 22 minutes until the top looks dry and the edges are lightly golden. Remove from the oven and let it cool on the pan for 5 minutes.
05 -
While the potato sheet bakes, heat olive oil in a skillet over medium-high heat. Add the ground beef and cook, breaking it up, until browned, about 5 minutes. Add the onion and cook for 4 to 5 minutes until softened. Stir in the garlic, tomato paste, paprika, salt, and pepper. Cook for 2 more minutes, then stir in the parsley. Drain any excess fat and let the filling cool for 5 minutes.
06 -
Spread the beef filling evenly over the baked potato sheet, leaving a 1-inch border on all sides. Scatter the remaining 1 cup of mozzarella over the filling. Using the parchment paper to help, roll the sheet up tightly from the long edge into a firm log. Place seam side down on the pan.
07 -
Bake the roll for 15 to 18 minutes until the outside is golden and crisp. The internal temperature at the thickest point should read 160°F (71°C). Remove from the oven and rest for 5 minutes before slicing into 1-inch rounds.