they are nice roasted- scrub them, cut if huge, put in roasting tray with olive oil and some butter, plus lemon zest and thyme (thank you Nigel slater) also in soup, with potatoes, creamed. they do make you fart though!
However, they are utterly delicious whizzed up into carrot-and-jerusalem artichoke soup. Made some yesterday and had it for dinner. Yum. It's wonderfully creamy and rich just made with the veg, an onion and some stock - no need for milk or cream.