COOK pasta as directed on package, omitting salt.
MEANWHILE, heat oil in large skillet on medium-high heat. Add chicken; cook and stir 5 to 6 min. or until no longer pink. Add peppers and mushrooms; cook 3 min., stirring occasionally. Stir in tomatoes and dressing; simmer on medium-low heat 5 min. or until chicken is done.
DRAIN pasta. Toss with chicken mixture; top with cheese and basil.