Preheat oven to 400°F (200°C). Line a baking sheet with parchment paper or a silicone mat.
While the oven is preheating, wash, dry and cut 2 pounds small red new potatoes into quarters. Place in a bowl or directly on the baking sheet.
Drizzle 3 tablespoons olive oil over potatoes, then sprinkle with 1 teaspoon dried rosemary, 1 teaspoon salt and 1 teaspoon pepper. Gently toss to coat.
Arrange potatoes in a single layer on the sheet pan. Roast potatoes for 25 minutes, until fork-tender. For crispier, golden brown potatoes, cook for an additional 10 minutes.
Notes
Storing leftovers: Place leftover rosemary potatoes in an airtight container. Let them cool completely before sealing so condensation doesn't make them soggy. Place the container in the fridge and enjoy within 4 days.To reheat: Cook in the oven or an air fryer at 400°F (200°C) for 10 minutes to get them crispy again. (The microwave works in a pinch but they'll be softer.)Freezing leftovers: Roasted potatoes freeze surprisingly well. Let them cool completely, then spread them in a single layer on a baking sheet to freeze solid before transferring to a freezer bag or airtight container — this keeps them from clumping together. They'll keep for up to 3 months. Reheat straight from frozen in the oven or air fryer at 400°F (200°C) until heated through and crispy again, about 15–20 minutes. No need to thaw first.