Preheat the oven to 425 degrees F (220 degrees C). Line a baking sheet with aluminum foil.
Mix potatoes, olive oil, Parmesan cheese, and rosemary in a bowl. Season with salt and pepper. Spread potato mixture over the prepared baking sheet.
Bake in the preheated oven for 20 minutes. Stir potatoes, then continue to bake until golden brown and tender, about 20 more minutes.
