Rinse the rice a couple of times in water and then soak in enough water for about 30 minutes.
Meanwhile when the rice is soaking, take full-fat milk in a heavy bottom pan.
Bring it to a boil and add soaked and drained rice.
Simmer and cook rice on low heat without the lid on. Keep mashing the rice at regular intervals with the back of the ladle while cooking.
Meanwhile continue to stir the milk rice mixture so that it should not stick to bottom of the pan. If required keep adding few spoonfuls of water.
Scrape milk solids from the sides of the pan and keep adding to the kheer.
Simmer till the rice is almost cooked and well incorporated. The rice grains shouldn't be seen separate from the milk.
Continue to cook on low heat till the rice kheer thickens and the rice is almost mashed. This would take approximately 30 to 40 minutes.
Add cardamom powder and mix. Also add the sliced nuts and simmer for 2 more minutes and switch off the flame and keep aside to cool for about half an hour.
Once cooled add grated Date palm jaggery and stir well.
Let it rest for 10 minutes until the jaggery slightly dissolves.
Now, transfer the pan back on the stove and cook it on very low heat until the jaggery melts completely. Garnish with slivered nuts.
Your delicious Rice Kheer is ready. Serve it either hot / warm or let it chill in the refrigerator and serve it cold.