Wash, cut and peel potatoes. Chop potatoes into small pieces. In a pot filled with water, add potatoes and cover. Add a pinch of salt. Boil for 20 minutes. While potatoes are boiling, finely chop garlic. Once potatoes are soft, place in heated frying pan with oil, rosemary, and garlic. Mix well, coating the potatoes with the oil. Fry for about 20 minutes. Stir occasionally to brown all sides of the potatoes.