Preheat oven to 375-degrees. Brush the bottom and sides of a cast iron skillet with olive oil. Slice potatoes crosswise into desired thickness. Arrange potato slices loosely in skillet and sprinkle with garlic, Italian seasoning, salt and pepper. Add small pieces of cubed butter on top of potatoes, spread out. Cover skillet with foil and bake for 1 hour, or until potatoes are tender. Remove foil, sprinkle with Parmesan cheese and bake uncovered for another 15-20 minutes, until crisp.