Heat the evaporated milk and sugar in a pan. Stir continuously on a high heat, making sure the mixture does not burn, for 10 minutes. Set aside.
Put the pistachios into a food processor and blitz until the pistachios are finely chopped. Get the seeds out of the cardamom pods and crush them in a mortar and pestle into a powder.
Stir the pistachios, cardamom and double cream into the evaporated milk mixture. With cling film, line a non stick loaf tin, and pour in the Kulfi mixture. Put in the freezer for a minimum of 5 hours. Remove from the freezer, pull the Kulfi out of the mould, peel off the cling-film and serve with the chopped fresh mango and extra pistachios.