Celeriac is the less respected cousin of celery.
I actually prefer it over celery. For many reasons. Some being it over winters better than celery, the leaves and stems do not get as woody like celery can, and the large root can be roasted in a winter oven for some amazing meals (you can look up many recipes online).
As for me, celeriac is another reliable winter vegetable that scoffs at most winter weather. I never need to place over it fleece or a low tunnel. And from which I can constantly pick off leaves for salads all winter, or harvest a full root for a great winter celery soup.
Celeriac is very easy to grow and very forgiving. It can be difficult to sow and start directly, but sowing in seed trays, pricking out, and transplanting starts solves most of those issues and one can get a nice thick patch of celeriac rather easily.