Wash the rice thoroughly until the water running off from it is no longer cloudy, but clear. Then soak it for at least half an hour.
Drain the rice and add it to a slow cooker along with the milk and any flavorings (saffron/cardamom).
Set the slow cooker to low for about 6 hours. Stir occasionally (I only stirred it 2-3 times over the 6 hour period).
Once the kheer has thickened to your desired consistency stir in the sugar. You can start with 2 cups and keep adding more until it’s at the sweetness level that you want.
Please note that it should taste a little sweeter than the desired result when warm because things taste less sweet once they are cooled.
Chill in the refrigerator for a few hours before garnishing and serving.