Add the onion to the oil in the skillet and cook over medium heat until tender, about 3 minute Add garlic, rosemary, salt, pepper, and flour, and stir till onion is evenly coated. Add broth and simmer until thickens slightly; pour over potatoes. Cover with folded kitchen towel and top with the lid. Cook 3-4 hours on high, or 6-8 hours on low, until tender. Remove the towel, scatter cheese on top, cover, and cook 3 minute or till cheese melts.
