Marinate pork in 1/3 cup (75mL) Balsamic vinegar salad dressing for one hour or overnight. Pre-heat oven to 425°F (220°C). Sprinkle pork with salt and pepper to taste and place in a shallow baking pan. Roast, uncovered, for about 25 minutes or until a meat thermometer reads 150°F (66°C). Allow pork to rest 10 minutes before slicing. Serves 2-3.