Coat the pork tenderloins well with salt & pepper, then in a large frying pan, heat vegetable oil over medium-high heat until it begins to smoke.
Sear pork on all sides, about 2 minutes per side, then turn off the heat & transfer the meat to a shallow baking pan.
Roast the pork for about 25-30 minutes or until internal temperature reaches 140 degrees F.
While pork is cooking, pour off the excess oil from the frying pan, then place the pan over high heat & add the garlic, cooking for just 30 seconds before adding the vinegar, cherry preserves & chicken stock.
Cook until sauce reduces by about half & begins to slightly thicken, about 5 minutes.
Turn off the heat & whisk in the cold butter, stirring constantly until the butter is gone, then taste & adjust the seasoning, if necessary.
When meat is done, remove it from the oven to a platter, allowing to rest for 10 minutes before slicing. Serve with the warm sauce.