Horta, as the wide array of wild greens are called in Greece are easy to prepare.  Simply clean them and boil them in water; the dandelion greens and chicory need to cook for about an hour, but some of the younger and more tender shoots can be ready in ten minutes.  Some varieties are extremely bitter, in this case some people prefer to change the water after boiling for awhile to take away some of this bitterness, most greeks don't do this because they like the bitter (and it's good for you!). People will often mix varieties of horta and cook them together, even adding fennel or other herbs for different flavor combinations.