To prepare chutney, melt 1 teaspoon butter in medium saucepan over medium heat. Add onion; cook 4 minutes or until tender. Add nectarine, cranberries, and vinegar; cook 3 minutes or until nectarine is tender. Remove from heat; stir in 1/4 teaspoon salt, cinnamon, cloves, and remaining 2 teaspoons butter.
To prepare pork, cut pork crosswise into 8 (1-inch-thick) slices. Place each slice between 2 sheets of heavy-duty plastic wrap; pound to 1/2-inch thickness using a meat mallet or small heavy skillet. Sprinkle pork evenly with 1/2 teaspoon salt and pepper. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add pork; cook 3 minutes on each side or until desired degree of doneness. Serve pork with chutney.