Fennel is among my favorite cold-weather staples. Oddly enough I like the pairing of fennel and celery. Though their textures are similar, their flavors are so wildly different that the combination is striking. With little more than olive oil, loads of lemon juice, and pepper (and some Parmesan, why not?), they create just about as refreshing an uncooked dish as you can put on the table this time of year.