Heat oven to 325℉. Pat the pork dry with paper towels, and then season it with salt and pepper.
Place a cast iron skillet (or other oven safe skillet) over medium-high heat and add the vegetable oil. When the oil is very hot, but not smoking, place the pork in the skillet fat side down. Cook until that side is well browned, about 3 minutes. Using tongs, rotate the pork and continue to cook until well browned on all sides. Then transfer to a plate and set aside.
Reduce the heat to medium and add the wine to the skillet. Using a wooden spoon, stir to loosen any browned bits on the bottom of the skillet, and allow the wine to simmer and reduce slightly (about a minute or two).
Add the savory cranberry sauce and stir to combine with the reduced wine to make the glaze.
Return the pork to the skillet. Using tongs, roll the pork to coat with the glaze on all sides.
Place the skillet in the oven and roast until the pork reaches an internal temperature of 145 degrees, about 30 to 40 minutes. About halfway through the roasting process, use tongs to roll the pork in the glaze once again (being careful not to touch the hot skillet handle).
Transfer the pork to a carving board and allow it to rest. In the meantime, put the remaining glaze in a vessel suitable for pouring.
Remove the twine and carve the pork into ¼ inch slices. Serve with a generous amount of the remaining glaze poured over the top.