and let steep for 20 minutes. 3. Pour the prunes and liquid into a blender or food processor and buzz until smooth. Season with salt and pepper to taste. 4. Heat the oil in a large skillet over medium-high heat until hot. Season both tenderloins well with salt and pepper and sear one at a time, turning occasionally, until brown, about 5 minutes. Transfer to a baking sheet and set the skillet aside. 5. Roast the pork until an instant-read thermometer inserted in the center of the meat registers just under 150Â°F, 15 to 18 minutes. Transfer the tenderloins to a cutting board, tent with foil, and let rest for 5 minutes. 6. Pour o all but a thin lm of fat from the skillet. Lower the heat to medium, toss in the garlic, and cook until lightly colored, about 2 minutes. Add the port-prune sauce and stir to pick up the browned bits stuck to the skillet. Pour in the vinegar, and any accumulated juices from the pork, and cook to meld the avors, 2 to 3 minutes. If the sauce seems thick, add more beef stock. For an elegant take, strain the sauce through a sieve. 7. Cut the tenderloins on the diagonal into Â˝-inch slices. Divide the slices among six plates, drizzle with the warm sauce, and sprinkle with cilantro.