Combine first 3 ingredients in a large nonstick skillet; bring to a boil over medium-high heat. Boil 3 minutes or until liquid is absorbed. Remove from pan, and cool.
. Coat chicken with cooking spray. Sprinkle both sides of chicken with pepper and 1/8 teaspoon salt. Heat pan over medium-high heat; add chicken, and cook 6 minutes on each side or until done.
. Combine onion mixture, yogurt-based spread, and remaining 1/8 teaspoon salt; spoon over chicken. Let stand 1 minute before serving.