Place 2 chicken breasts in large freezer-weight resealable plastic bag. Pound chicken with the side of a heavy can, rolling pin or meat mallet until chicken is 1/4-inch thick. Remove chicken from bag; set aside. Repeat with remaining chicken breasts.
Serve with hot egg noodles and a tossed green salad.
Omit sweet vermouth. Increase the chicken broth to 1-1/2 cups.