HEAT 2 Tbsp. dressing in large skillet on medium heat. Add chicken; cook and stir 5 min. or until chicken is cooked through.
STIR in remaining dressing, water, broth, soy sauce and peanut butter. Bring to boil. Add pasta. Cover. Simmer 5 min.
ADD vegetables; mix lightly. Simmer, covered, 4 to 6 min. or until pasta is tender.