Shred potatoes using either a food processor or a hand grater. Place the potato shreds in cheese cloth, and squeeze out any excess liquid. Place these potato shreds in a mixing bowl.
Add these ingredients to the same mixing bowl: scallions, garlic, rosemary, egg, flour, Parmesan cheese, salt, and pepper. Mix the ingredients well. Roughly divide the mixture in half, and then divide each half into thirds so you end up with 6 piles. This will give you an idea of how much mixture to form for each of the 6 latkes.
Heat olive oil in a large shallow pan over medium heat. Scoop up a pile of potato mixture and roughly form in the shape of a patty and place it on the pan. Each latke will hold its shape once heated. Repeat for all six latkes.
Cook each side of the latke until crisp and browned to your liking, at least 5 minutes per side. You can press down on each latke with a spatula to give it a nice sear. Serve immediately.