I had a pork tenderloin left over after I made the pamplona a couple of days before and I wanted a quick and easy way to make it. I got this suggestion from a user of the craigslist food forum who uses the moniker "Voltaire".
Marinade the pork tenderloin in olive oil and balsamic vinegar, with some chopped garlic and rosemary. I didn't have rosemary so I ommitted it but I did add a tablespoon or so of hoisin sauce to the marinade. Then we grilled it over medium-low heat until done. It was very good, in particular the outside part that had caramelized with the marinade. Next time I'll butterfly the tenderloin so as to maximize the caramelized area.