Preheat oven to 375°F.
Place pork in a shallow roasting pan or grill pan and pat dry with a paper towel.
3 pounds boneless pork loin roast
Rub all sides with olive oil.
2 tablespoons olive oil
Season with salt and pepper on all sides.
2¼ teaspoons kosher salt, Freshly ground black pepper
Sear each side over high heat for 2 minutes per side, 10 minutes total.
While searing, make your sauce: In a medium bowl, stir together the ½ cup orange juice, vinegar, marmalade, and cranberry sauce.
¾ cup orange juice, ¼ cup apple cider vinegar, 8 ounces sweet orange marmalade, 7 ounces whole cranberry sauce
Place seared pork in a large roasting pan and pour sauce over the pork.
Roast for 60-80 minutes, or until internal temperature reaches 140-145°F in the most central part of the pork. Baste every 20 minutes in the orange juice mixture.
Remove from oven and place pork on a foil tented plate to cool/rest for 10 minutes.
While pork is resting, add the remaining ¼ cup of orange juice to the juices left over from cooking. If your roasting pan is stovetop safe you can just keep all the sauces in the pan or if not, add to a saucepan.
Bring sauce to a boil and then reduce to a simmer while pork rests.
Slice and serve pork, drizzled with more sauce and garnished with orange slices and fresh cranberries.