When the rice is added, then bring back to boil and turn heat down to simmer for 5 mins. Having said that, that was the method that was given to me. My recommendation would be simmer for 5 mins, give it a good stir, then put lid back on, with the heat turned as low as it will go, so the rice steams in the remaining liquid until it is completely absorbed. Then a good going through with a fork to separate the grains, then lid back on without any heat for the rice to fluff up.
you've got me thinking that I just typed the recipe and method in as given to me, then did these extra things myself... maybe I should have been more methodical with typing the method up!!