Preheat oven to 425°. Sprinkle pork with salt and pepper. In a large ovenproof skillet, heat oil over medium-high heat. Brown pork on all sides. Remove pork from pan., Remove pan from heat; add vinegar, stirring to loosen browned bits from pan. Stir in brown sugar. Return pork to pan, turning to coat., Bake 8-10 minutes or until a thermometer reads 145°, turning occasionally. Remove pork to a serving platter; tent with foil. Let stand 5 minutes before slicing. Pour glaze over pork before serving.