Not normally considered to be "herbal," but I think it is

A friend of mine is grilling today and uses hickory chips to make a smoker from the grill. Any fruit wood will work, chipped small, and many people use mesquite, (which is awfully easy to overdo).

You take 1/2 pint of chips and you fill the pint jar with hot water. Let them soak an hour.

When your coals are ready, put them all on one side of the grill. Drain the chips well and put the damp chips atop the coals. Put the burgers on the other side of the grill from the coals. 10 minutes per side. Check the temperature to make sure the meat is done. Enjoy the added flavor of hickory smoke on your burgers!