In a bowl, combine the chicken, chilies, broth, soups and onion; set aside. Warm tortillas in the microwave according to package driections. Layer half of the tortillas on the bottom of a greased 13x9x2 inch baking pan, cutting to fit pan if desired. Top with half the chicken mixture and half of the cheese. Repeat layers. Bake, uncovered, at 350� for 30 minutes.