1. Scrub potatoes under running water and trim away any blemishes. Pat them dry, sprinkle with olive oil, toss, cover with foil and bake for about 1 hour (or more, check for doneness by piercing with a fork). Let cool and cut into bite-size cubes, leaving the skins on. (You can boil the potatoes instead. Place them in a pot, cover with cold water, bring to a boil, cover and cook for about 15 minutes, or until tender).
2. Place bacon in a cold skillet. Cook until crisp, drain and crumble.
3. In a small bowl, combine olive oil, vinegar, salt and pepper.
4. In a large bowl, combine potatoes, green onions, bacon and cheese. Pour the dressing over the salad and toss to coat. Refrigerate for at least 1 hour.