Blanching vegetables is a method of partially cooking vegetables through the plunging of them briefly into boiling water. It can be a way of preserving nutrients so that you can freeze the vegetable or a method of keeping the vegetable crisp for a salad while making it easier to digest.
Fennel is a fall vegetable, and if you want to freeze some for out-of-season use, you can try this method.
Readying the Fennel
Cut out and discard the core of the fennel. Slice the fennel bulb thinly, as if using for a salad.
Discard the stalks and fronds; these do not freeze well.
Bring a large pot of water to boil.
Put the fennel in the pot, being careful not to splash yourself.
Cook for 3 minutes.
Drain the fennel in the colander and rinse it with cold water to stop the cooking.