This A - Z tickled me; it includes a tremendous summary of the role of witloof..
"A curious bitter vegetable that is positively venerated by Belgians. Surprisingly good in soup, but best drenched in cheese and baked thoroughly. Adoration of this vegetable reaches its peak during the winter season, when crowds can be season inspecting and sniffing candidate purchases at market places. Referred to as "chicory" in other countries and usually fed to pigs."