Julienne is a specific way to chop vegetables, usually used in French cooking. In fact, the word "julienne" comes from the French word for "matchstick," since slicing vegetables julienne makes them into matchstick-like shapes. While it may be easy to julienne most vegetables, some round vegetables, like fennel, can be a little more difficult. Still, if the vegetable is separated into more manageable sections, it's easy to julienne fennel or any other round vegetable.
Cut off the leaves and stalks at the top of the fennel bulb and peel off the outer skin of the bulb.
Slice the fennel bulb in half and cut the core (the middle section at the bottom) out of each half.
Lay half of the fennel bulb flat on the cutting board and slice across the bulb to make 1/4 inch thick panels.
Stack the thin panels of fennel on top of each other and slice them across 1/4 inch at a time to make small matchstick-like pieces of fennel.
Repeat the process with the other half of the bulb.