Preheat oven to 400°F (200°C), placing rack on lower third for extra crispness.
Rinse and pat potatoes dry. Halve any larger ones for even cooking.
In a bowl, combine potatoes, olive oil, garlic, rosemary, salt, and pepper. Toss well.
Spread in a single layer on a rimmed baking sheet, cut side down if halved.
Bake for 20 minutes, shaking the pan every 5 minutes for even browning.
Potatoes should be fork-tender inside and golden outside.
Taste, adjust salt if needed, and serve immediately while hot.
