Beets, celery, onions, Swiss chard, and green beans cook particularly well on the griddle—yes, that pan you pull out only for Sunday-morning pancakes. Griddles allow vegetables to retain as many antioxidants as microwaving, according to the Spanish researchers. Word of caution: Griddles are often coated in nonstick chemicals that make cooking and cleaning convenient but may contain toxins linked to cancer. Shop for one without the coating, or use a thick frying pan with no oil.
Photo: (cc) Jeremy Keith/Flickr