COOK pasta as directed on package, omitting salt.
MEANWHILE, cook chicken in hot oil in large nonstick skillet on high heat 3 min., stirring frequently. Add peppers; cook and stir 2 to 3 min. or until crisp-tender. Stir in tomatoes; bring to boil. Simmer on low heat 10 min., stirring occasionally. Add Cheez Whiz; cook 1 min. or until Cheez Whiz is melted and mixture is well blended, stirring frequently.
DRAIN pasta. Add to chicken mixture; mix lightly. Cook 2 to 3 min. or until heated through, stirring frequently.