01 - Preheat the oven to 425°F and prepare a large baking sheet by lining it with parchment paper or lightly greasing with olive oil.
02 - In a large bowl, combine potato pieces with olive oil, rosemary, salt, pepper, and garlic if using, tossing until evenly coated.
03 - Spread the potatoes in a single layer on the prepared sheet with the cut side facing down to enhance crispiness.
04 - Roast potatoes for 30 to 35 minutes, turning once midway through, until golden brown and crisp along the edges.
05 - Remove from oven, taste and adjust seasoning as needed. Serve hot, optionally garnished with extra rosemary.