1. Heat oil in a small saucepan over medium-high heat. Add shallots and garlic; sauté 2 minutes. Add vinegar and next 3 ingredients; cook until reduced to 1/2 cup.
2. Heat a large skillet over medium-high heat. Coat pan with cooking spray. Sprinkle pork with salt and pepper. Place pork in pan; cook 2 minutes on each side. Add balsamic reduction; cook 1 minute, turning pork to coat.