Heat gas or charcoal grill. On each of two 11-inch metal skewers, thread chicken, bell pepper and mushrooms alternately, leaving 1/2-inch space between each piece. Brush kabobs with dressing; sprinkle with pizza seasoning.
Cover and grill kabobs over medium heat 9 to 11 minutes, turning once, until chicken is no longer pink in center. Sprinkle immediately with cheese.
Meanwhile, in 1-quart saucepan, heat pizza sauce over low heat. Serve kabobs with warm sauce.