COOK pasta as directed on package. Meanwhile, cook chicken and onions in hot oil in large skillet on medium heat 6 to 8 min. or until chicken is done, stirring frequently. Add peas, peppers and garlic; cook and stir 1 min. Remove from heat; cover to keep warm.
MELT butter in medium saucepan on medium heat. Stir in flour until well blended. Gradually stir in milk. Bring to boil; cook 2 min. or until thickened, stirring constantly. Add cream cheese and Romano; cook 1 to 2 min. or until cream cheese is completely melted and sauce is well blended, stirring constantly.
DRAIN pasta; place in large bowl. Add chicken mixture and sauce; toss to coat. Top with parsley.