Season the pork roast generously with salt and pepper and let sit at room temperature for about 1 hour.
Preheat oven to 375 degrees. Pat the roast dry with paper towels.
Heat an oven-proof skillet large enough to hold the roast over medium-high heat. Add the oil and let heat until it starts to shimmer. Sear the roast on all sides (don’t move the roast until it is browned on one side, then turn), about 10 minutes. Remove the roast from the pan and brush it with some of the Sweet & Tangy sauce. Wrap the bacon around the roast. Wipe out the pan and set the roast back in it. Roast for 35-40 minutes or until it reaches an internal temperature of 145 degrees. Turn the broiler to high and crisp up the bacon, about 2-3 minutes. Remove the roast from the pan and place on a serving platter. Tent with foil and let rest while you make the sauce.
Wipe out most of the bacon fat from the pan and pour in the rest of the Sweet & Tangy sauce along with the pineapples. Cook over medium-high heat until heated through. Stir in the green onions and spoon the sauce over the roast.