2. Spray heavy skillet-grill or 12-inch skillet with nonstick cooking spray. Heatskillet over medium-high heat until very hot.
3. Meanwhile, toss chicken-breast halves with lemon-juice mixture.
4. Place chicken-breast halves in hot skillet; cook 5 minutes, brushing with remaining lemon-juice mixture in bowl. Turn chicken over and cook 5 minutes longer until juices run clear when thickest part of chicken breast is pierced with a knife. Garnish with lemon slices.