Add the milk, heavy cream & cardamom powder in a wide heavy-bottom sauce pan.
Bring to a simmer while stirring often until the liquid has reduced to half it's original volume. This takes about 20-30 minutes.
Add the sugar and stir until dissolved. Then stir in the vanilla and salt and turn off the heat.
Transfer the mixture to a bowl and set in a larger bowl with ice-water to cool the mixture down, stirring occasionally until it's at room temperature.
Pour the mixture into six 41/2 ounce molds (I used dixie cups) and freeze them until solid (minimum 24 hours).
For the citrus fruit in syrup. Add the sugar and water in a sauce pan along with the sliced ginger until the sugar has dissolved and thickened slightly.
Take the pan off the heat and let it cool to room temp. Take out the ginger or strain the syrup
Cut the citrus fruit into segments or suprêmes, squeeze the membranes to get all the juices to set aside.
Add 1/2 tsp rose water to the room temp syrup and pour the syrup over the citrus fruit segments and juices
Let it steep for at least an hour or in the fridge for longer.
To serve; simply spoon some of the citrus fruit and syrup on the bottom of a plate/bowl and unmold the kulfi (just tear the paper cups off) onto the plate/bowl.
Top with chopped pistachios and dried rose petals.