Preheat a 8-10″ cast iron skillet over medium high heat.

When the pan is hot, add the olive oil and swirl to coat the bottom of the pan. Add the potatoes and half the chopped rosemary in the skillet. I add the sea salt in at this time, but you can season to taste at the end if you think you may use less.

Cook over medium high heat for about 15 minutes. Use a metal spatula to mix in the rosemary and sea salt if you’re adding it at this point. Then stir to flip the potatoes only when the bottom layer turns brown and crispy.

After about 15 minutes, turn the heat down to medium. If the pan starts to get too hot before the 15 minutes is up, turn the heat down sooner.

Add the rest of the rosemary and continue to cook over medium heat. Continue to turn over the potatoes when brown edges appear on the bottom layer.

Cook until the potatoes are tender with crispy brown edges, 10 more minutes.

Season to taste with sea salt, and serve immediately.