fennel can be a difficult vegetable to cook due to its layers which can easily fall apart cooking it sous-vide will keep the bulbs intact and the consistently low temperature guarantees the perfect texture trim the woody base and tips off the fennel and cut into wedges put the wedges into a vacuum bag in a single layer with a little olive oil and salt vacuum seal the bag you could boost the aniseed flavor of the fennel by adding a star anise to the bag before sealing place the bag in the preheated water bath to cook for 45 minutes remove the fennel from the bag and drain it on kitchen paper before serving