In a large, heavy bottom pan (cast iron is great) heat the peanut oil until it registers 350-375 degrees. Try to maintain this cooking temp throughout. Peel potatoes and cut into 2" disks. Carefully lower them into the hot oil and "slow cook" the french fries. Watch the oil and make sure it's not too hot or cold. If it's too hot they will burn, too cold they will be greasy. Add sprig of Rosemary to pot and let cook until potatoes are just tender. While potatoes are cooking, grate or shred mozzarella. When potatoes are cooked through, carefully lift them out of the oil and place on a baking sheet. Immediately sprinkle with Kosher salt, black pepper and Italian Seasoning to taste. Top with fresh mozzarella and greated parmesan and put into a hot oven (450 degrees) for 5-7 minutes or until the cheese melts. Sprinkle with chopped scallions and serve at once.