In a small bowl, add 2 tbsp of cold water to the cornflour and mix into a paste. In a large pan, combine the milk, sugar and rose water and simmer for 2 mins until the sugar has dissolved. Stir the cornflour mixture into the milk and bring to the boil, stirring constantly for 1 min. Turn off the heat. Soak the gelatine sheets in a bowl of cold water for 5 mins, then squeeze out and add to the milk mixture. Allow to cool slightly then add the pistachios. Pour into six tea cups and chill for 2 hours. To serve, sprinkle over the remaining pistachios and rose petals.
Makes 6 1 litre whole milk 50g cornflour 75g sugar 4 tbsp rose water 4 sheets of gelatine 4 tbsp crushed pistachios, plus extra for decoration dried edible rose petals, for decoration