slice off the end of the core slightly. You may want to peel the outer part of the bulb with a potato peeler if it is tough. Slice thinly starting at the root end. There will be the core on the inside of the slices. If you don't want that, simply remove, however, it cooks and becomes tender just like the rest of the bulb. Slice up to the stalks. Save the stalks to flavor broth.