Cook the rice in boiling salted water for approx. 20 mins. until just soft, drain, rinse with cold water. Heat the butter in a frying pan, brown the corn cobs all over for approx. 5 mins. Remove the corn from the cobs using a knife, mix with the rice.
Mix the yoghurt with the vinegar and coriander, season. Mix the rice with half of the dressing, plate up. Drizzle the remainder of the dressing on top.