I have harvested a couple small batches of chicory this summer and fall. Both times it turned out really good. In my experience, I learned that after washing, chopping the roots in to very small pieces helps in the grinding process after the roasting. At least MY chicory is super tough and woody stuff and extremely difficult to grind, (I actually used a meat grinder). But the second round I chopped the roots in to small uniform pieces for even roasting, and ease in grinding. One thing I did notice about the structure of the roots themselves is that there tends to be a very tough inner core surrounded by a much softer, fleshy type material on the outside of the root. I processed and roasted both parts but was unable to find anything online about which part of the roots might be more valuable in this application. Still, I found the whole process to be rather easy and intuitive. It has a great flavor, totally worth doing!