HEAT oven to 425ºF.
COMBINE potatoes and peppers in large bowl. Mix dressing and garlic until blended. Pour half over vegetables; toss to evenly coat.
PLACE chicken in roasting pan sprayed with cooking spray; brush with remaining dressing mixture. Spoon vegetables around chicken.
BAKE 1 hour or until chicken is done (165ºF) and vegetables are tender, reducing oven temperature to 350ºF after 30 min.
TRANSFER chicken and vegetables to platter; sprinkle with cilantro.