Melt the chocolate with the cream, milk and sugar in a heatproof bowl suspended over a pot of simmering water.
Once melted, whisk until the sugar dissolves then stir in the cardamom.
Meanwhile, soak the gelatine leaves in cold water for five minutes. Squeeze out excess water and dissolve in the warm chocolate mixture. Pour into mould and allow to set in the fridge for at least one hour.
Bring all the ingredients for the rose syrup to a boil with 2 tbsp of water and then bring to the boil and then allow to infuse for 30 minutes.
Strain into a jug and reserve for plating.
Unmould the panna cotta and place into the middle of the plate. Spoon around the rose syrup, arrange pomegranate, rose petals and a sprinkling of pistachio on the plate.