Pour over the stock, then cover and bring to the boil. Stir quickly, then cover again and place on the lowest heat possible. Simmer for 10 mins. Turn off the heat and leave, covered, for a further 10 mins. If serving straightaway, stir through the coriander and spring onions; alternatively, leave the rice to cool, chill, then re-fry before serving and stir the coriander and spring onions through at the end.