Identification: These sturdy, flavorful greens are nearly always cooked because they are too tough to eat raw, unless very young. The kale varieties have curly or ruffled dark green leaves (except the ornamental varieties, which may have touches of red or other colors). Turnip greens resemble large, lobed mustard or arugula leaves. Collards are similar, generally with heavier stems and more rounded leaves.
Evaluation: Avoid browned, yellowed, or dried leaves. Look for smaller leaves that are dark green and have a moist feel.
Preparation: Strip the leaves off the stems if they are tough. Cut off any discolored parts. Wash well in several changes of water.