Oh, Fiorentina!

...And stand it upright on the bone on the grill for a few minutes to drive heat in from below as well. As for how done, Dario says rare; the best way to judge the doneness of a steak is by feel (quick course here), and if you want it more done that's your choice.

Note: This shot is out of sequence, from the grill in our den. Italian butchers often trim some of the bone from a thick steak on the theory that if it's bone you won't be eating it and therefore won't want to pay for it. Do not have the bone trimmed if you plan to stand the steak up, because it won't stand upright if you do. These steaks were each a bit more than 2 1/2 pounds (1.2 k).