Eating your greens is an integral part of a healthy lifestyle, and supermarkets are stocked with a greater variety than ever before. Martha provides an overview of the most popular greens while making some of her favorite recipes - delicate sorrel soup, a heady pasta dish with grilled sardines and bitter greens, a versatile Swiss-chard frittata, a trendy kale Caesar salad and a new take on a popular salad green, spicy escarole. You'll be inspired to expand your greens repertoire.