Typified by sturdy leaves. Includes kale, Swiss chard, endive,
escarole, and mustard and collard greens. Because of their strong taste
and tougher texture when mature, greens are most often boiled,
stir-fried or sautéed. When buying, look for crisp, brightly colored
greens and avoid any with wilted or yellowed leaves. Smaller leaves
with thin stems will be milder tasting and can be used for salad. Also
known as potherbs.