Preheat oven to 400° F.
Spray a casserole with cooking spray.
Place chicken and pesto in medium bowl; toss to coat.
Place chicken in prepared casserole.
Sprinkle chicken with drained tomatoes.
Bake for 20 to 25 minutes or until chicken is no longer pink in center.
Remove from oven; top with cheese.
Bake for an additional 3 to 5 minutes or until cheese is melted