Preheat the oven to 375 degrees. Heat the oil in a large ovenproof skillet over high heat. Season the pork with salt and pepper and sear on all sides until golden brown. Combine the mustard and vinegar and rub over the pork. Transfer to the oven and roast the pork until a thermometer inserted in the center reads 145 degrees, about 35 minutes. Transfer the pork to a cutting board and tent with foil for 10 minutes. Re-cut into strings, slice and serve with Fall Vegetable Cobbler