I made this one year for a holiday dinner party. I had found two similar recipes in magazines that I combined to create this one. My only mistake was slightly over cooking the pork....nothing worse than overcooked and dry pork.
Mix together spices (first six ingredients) in a bowl. Sprinkle over pork, place in a resealable bag, and allow to refrigerate for 1-4 hours.
Bring oil to high heat in large saute pan (oven proof). Sear off each side of the pork tenderloin, quickly, but ensuring a nice brown crust. Place the pan, with both tenderloins in a 375 degree oven for 30 minutes, or until the internal temperature reaches 155 degrees. Remove pork from oven and pan, cover in foil, and allow to rest for 10-20 minutes. Do not discard the juices from the pan.
In the pan (that was just used for the pork), prepare the sauce by adding 2 teaspoons of the adobo sauce, syrup, stock, and vinegar and stirring at a medium heat. Use a whisk or spoon to scrape up any brown bits at the bottom of the pan. Stir constantly for about 5-6 minutes. Taste for seasoning and add salt/pepper if desired.
Serve pork in slices with a drizzle of sauce.
This dish goes VERY well with creamy roasted garlic mashed potatoes and fried apples.