Cut potatoes in approximately 1" chunks (I usually quarter or sixth the potato, depending upon size). Press out excess moisture*.
Toss potatoes with oil, rosemary, and salt. Spread out on a baking sheet*.
Bake for 45 minutes to 1 hour, stirring every 15 minutes, until golden/crisp on outside and tender on the inside.
Notes
*To press out moisture, spread out potatoes on a dish towel. Place another towel on top. Press and rub gently to remove excess moisture from potatoes. This is an important step. **Do NOT use foil on baking sheet. When you stir, the potatoes will stick and you will end up with small bits of foil all over the potatoes.