Add the chicken broth, one soup ladle at a time. Let each ladle full of broth fully absorb into the rice before adding more. You will need to stir the rice often, almost continuously, at this point. You want the broth absorbing into the rice lightly simmering, not at a full boil, in order to give the rice time to fully cook, so adjust the heat as needed. When you are down to the last ladle or two of broth, taste the rice before you add more. The rice is done when it is al dente (fully cooked, but firm to the bite).