Add potatoes to a saucepan and cover with cold water. Add salt to taste and bring to a simmer. Cook for 5 minutes. Drain thoroughly and allow to cool completely.
Warm the oil in a heavy frying pan over medium-low heat. Add the garlic and sauté gently until just beginning to color and soften, about 10 minutes. Use a slotted spoon to transfer potatoes to a plate. Set aside.
Increase heat to high, add the potatoes and sauté, shaking the pan back and forth, until almost tender, about 12 minutes.
Add the sautéed garlic, rosemary and salt to taste. Continue to sauté until the potatoes are crisp and golden, about 2 minute more.
Transfer to a serving dish and serve at once. Have guests squeeze the garlic cloves from their papery sheaths onto their own servings.