Pour the broths into a heavy pan and bring to boil. Lower heat.
Remove one cup of broth and mix it with the cornstarch; mix well.
Pour this mixture into the broth and simmer until it thickens. Place the chicken, carrots, onions and peas into the broth and cook until the chicken is heated through. Place about 2 tablespoons of this mixture into bread slices and put into sandwich maker. Cook for approximately 4 minutes or until it is well browned.