Take a coconut, break it, and cut into large pieces. Scrape away the brown skin if you want your coconut kheer to be absolutely white, or leave it as is.
Now, grate the coconut finely. Keep it aside when done.
Now, pour a liter of milk (full-cream preferred) into a heavy-bottomed pan and bring to gentle boil over a medium flame. Stir occasionally to prevent sticking at bottom. Boil the milk until it becomes little thicker. Check the consistency. Keep it aside.
In a separate kadai, heat 1 tsp of ghee (clarified butter) and fry the grated coconut for about a minute or two on a low flame until dry.
Now, pour the milk in the kadai. Mix the coconut nicely with the milk. Let the coconut and milk simmer on a low flame until they release their natural flavors. Scrape the malai from the sides to thicken the milk further and quicker.
Now, add 1 cup sugar (or jaggery) as per taste. Stir until the sugar is fully dissolved. Cook for another couple of minutes on a low flame. (Pro tip: If you are using jaggery to make the kheer, grate or dissolve jaggery separately in a little warm water before adding. This will help avoid graininess.)
At this stage, take 10 pieces each of cashew nuts, almonds, and pistachios on a plate. Chop them all. Also, take 10 pieces of raisins (whole), and add them to the kheer. Keep some of the nuts for final garnishing. Also, add 3 pieces of crushed green cardamom (elaichi) to it and mix all them nicely with the kheer. Let it cook for just a minute more or so.
Check the consistency. It should free-flowing at this stage because it will become denser when it cools. Switch off the gas stove. (Pro tip: If you want richer thickness, simmer for extra 2 to 3 minutes after adding sugar and cardamom, but avoid overcooking, else coconut might release too much oil or milk may separate.)
Transfer the kheer to a bowl and keep it in the fridge for about an hour to cool down.
Take the bowl out from the fridge after an hour. Your tasty and healthy coconut kheer is ready to enjoy. Garnish it with the remaining chopped almonds and cashew nut on top and serve.