Preheat your oven to 425°F (220°C). A hot oven is essential for achieving that perfect crispy texture.
Wash the red-skinned potatoes thoroughly to remove any dirt. Cut them into quarters or halves, depending on their size. Uniform pieces will ensure even cooking.
In a large mixing bowl, combine the olive oil, minced garlic, lemon zest, sea salt, and black pepper. Add the cut potatoes to the bowl and toss until they are evenly coated in the mixture.
Spread the coated potatoes in a single layer on the baking sheet. Make sure they are not overcrowded to allow for proper roasting.
Nestle the fresh rosemary sprigs among the potatoes. This will infuse the dish with aromatic flavors as they roast.
Place the baking sheet in the preheated oven and roast for about 30-35 minutes. Halfway through, give the potatoes a toss using a spatula to ensure they brown evenly.
Once the potatoes are golden brown and crispy, remove them from the oven. Transfer them to a serving dish and sprinkle with freshly grated Parmesan cheese. Serve warm and enjoy!