Mix rice, milk and nutmeg in a large bowl.
Cover with a film, pierce in 2-3 places and cook in the microwave at maximum power (I have 700) for 5-6 minutes.at the end: remove the film, stir and leave for 1 minute to cool.
Cover with clingfilm again and cook for another 5-6 minutes.
rice can fall apart already at this stage, and milk will almost be absorbed if the power of your microwave is 900 watts.