Of all of winter's hardy greens, none are more popular than the many members of the kale family, and dark green, red-stemmed Russian kale may well be the sweetest of all. The tips of the leaves are tender enough to be eaten raw, but they are infinitely improved by cooking. Not only does it tenderize the tough parts of the leaf, but it also brings to the surface a surprising sweetness you might not have expected was there.
Be careful: Russian kale has incredibly tough, woody stems, so be sure to remove as much of them as possible before cooking.
How to choose: Kale is incredibly hardy (why it's so popular as a winter garnish), but you still need to check the tips of the leaves and the cut ends of the stems to make sure they're not starting to soften.
How to store: Refrigerate in a tightly sealed plastic bag.
How to prepare: Simmer kale in olive oil and garlic with just the moisture that remains attached to the leaves after washing. The longer and slower you cook it, the sweeter it seems to get.