Transfer the pistachios and the seeds from the cardamom pods to a spice grinder and pulse until you have coarse powder. Do not over mix since this could result in the nuts releasing a lot of their oils. Set aside.
Pour 6 cups of whole milk into the heavy bottomed saucepan to reduce gently over medium to medium low heat. The milk needs to be reduced until the volume is reduced to half the original volume - 3 cups. See my Tip at the end of this recipe.
Continue to reduce the milk over a low heat, stirring every minute or so to make sure the milk doesn’t begin to stick to the bottom of the pan. This could take 45 minutes to an hour.
When the milk has reduced by half, turn off the heat.
Add the whipping cream, condensed milk, and the nut powder to the reduced milk and stir until they are fully combined. You can set aside a tsp of the nut powder for garnish, this is optional.
Turn the heat back on and reduce this mixture for another 20-30 minutes while stirring frequently until the mixture is reduced by 40% again. Use the same method as before to check if the mixture is reduced enough.
Turn the heat off and bring the mixture to room temperature.
Place the silicone or kulfi molds on a cookie sheet, spoon the kulfi mixture into the molds.
Transfer to the freezer and freeze for 6 hours, preferably overnight.