Split cardamom pods and sprinkle seeds in with coffee when brewing. Combine coffee, sweetened condensed milk and water. Sweeten to taste. Place mixture in metal bowl and freeze for 2 to 3 hours or until slushy. Remove from freezer and mash with whisk or fork until soft. Return to freezer and leave for 2-3 hours more.
You can also make this in an ice cream maker, which makes it easier to make in advance and keep in the freezer for a day or two, but it will have a slightly different texture.