Swiss chard seems to us two vegetables in one. It has long, flattened, celery-like stalks with large green leaves at the top. The two are cooked separately because the stalks take quite a bit longer than the leaves. Chard has become more familiar recently in the United States, right along with the popularization of other foods from the Mediterranean, where it is a much favored vegetable. Sautéed in olive oil with a sprinkle of vinegar or lemon juice at the end, it is served both hot and at room temperature as a salad. The taste is somewhat like spinach with a similar mildly earthy and slightly bitter flavor.