Slice the top and bottom of one of the oranges to expose the flesh. Using a small serrated knife, slice down between the pith and the flesh, working round the orange to remove all the peel and pith. Slicr the orange int 6 rounds, reserving any juice. Rep[eat with the remaining oranges.
Arrange the orange rounds on a serving dish. Mix the reserved juice with the rose water and drizzle over the oranges. Cover the dish with plastic wrap and chill for about 30 minutes. Sprinkle the chopped pistachio nuts over the oranges to serve.