Just a little experiment.  Some people take london broil to medium or so and slice really thin.  This was such a tough piece of meat I thought I'd experiment with a finishing method I've heard of and wanted to try.   Take the meat to 150*  and finish in a pressure cooker.     Marinaded, jaccarded and let it spin on the rotisserie getting exposed to the smoke for a while and finished with 30 min in a pressure cooker.  Made onion gravy with the drippings.   Onion gravy is sooooo good!!!