Put a large bowl in the freezer to chill. Put the sugar and measurement water in a wide saucepan and heat over a low heat until the sugar has dissolved. Meanwhile, cut the lemon rind into fine strips, crush the cardamom pods and split the vanilla pod in half. Add the lemon rind, cardamom and vanilla pod to the pan.
Add the apricots and simmer gently for 5 minutes, or until softened. Remove from the heat, add the lemon juice and rosewater and transfer to the chilled bowl. Leave to cool until required.
Spoon the apricots and a little of the syrup into serving bowls, scatter over the pistachio nuts and serve with ice cream or Greek-style yogurt, if you like.