Italian Chicken-Pasta Skillet

boneless skinless chicken breasts, cut into bite-size pieces

green pepper, chopped

small onion, cut into thin wedges

jar (24 oz.) OLIVO by CLASSICO Traditional Pasta Sauce

mostaccioli, cooked

pkg. (8 oz.) KRAFT Shredded Low-Moisture Part-Skim Mozzarella Cheese, divided