Rince it, wrap it in a cloth and put it in the lower part of your fridge. You can keep it for up to a week.
How to prepare
There are many ways to eat fennel. You can eat it in a salad. Chop it in cubes and ad you regular vinaigrette. If the liquorish flavour is too strong for you palate, do a vinaigrette with the juice of a fresh grapefruit or a fresh orange, like in this recipe. You can also bake them, like explained here. Both last recipes work with my 5 year old and 8 year old children. Hurray!