Long a staple of soul food, collard (also called collard greens and just plain collards) is a variety of cabbage that doesn't form a head but instead grows in a loose rosette at the top of a tall stem. It's often confused with its close relative kale and, in fact, tastes like a cross between cabbage and kale. Collard's peak season is January through April, though it's available year-round in most markets. Look for crisp green leaves with no evidence of yellowing, wilting or insect damage. Refrigerate collard in a plastic bag three to five days. The Southern style of cooking the greens is to boil them with a chunk of bacon or salt pork. They can be prepared in any manner suitable for spinach or cabbage. Collard is an excellent source of vitamins A and C, calcium and iron.