1. Preheat grill to medium-high heat.
2. Sprinkle both sides of chicken evenly with 1/2 teaspoon salt and 1/4 teaspoon pepper. Place chicken on a grill rack coated with cooking spray; grill 5 minutes on each side or until done. Let stand 5 minutes. Chop chicken.
3. Combine oil, rind, juice, and mustard in a large bowl, stirring well with a whisk. Add chopped, cooked chicken, nectarines, and remaining ingredients; toss well.