New Year's Day is approaching, which means we need to have a little talk about Hoppin' John. A savory blend of rice and black-eyed peas, it's served alongside collard greens as the traditional New Year's Day meal in the South and, increasingly, in other parts of the country. Eating those two dishes will ensure prosperity in the new year, and the collards represent greenbacks and the black-eyed peas coins. Or so they say. For a long time, if offered a plate of collards and Hoppin' John on New Years, I would have been inclined to say, "keep the change," for...