I've used fennel and I love the licorice-like flavor it adds! The first time I just used some of the white bulb and then I tried the stalk the second time around, but they seemed a bit more tough, stringy and pithy. The bulb seemed a bit more powerful in flavor. The ferny tops are edible too and can be used as a flavorful herb. Here's a graphic that shows how to prep fennel for the bulb portion.