Peel off the outer green layer of the watermelon (You can use the inside red part for juices or other purposes)
Cut it into small cubes and add the pieces in a grinder.
Heat a pan and put the grinded paste to the pan and keep stiring.
Make sure to stir frequently, until the water dries up.
Now add the powdered milk and crushed cardamom.
Mix thoroughly so that no lumps are formed.
Now add the sugar and salt and blend it until the water evaporates.
Add the milk and crushed nuts and stir evenly.
Add the ghee or butter
Voila! Your watermelon halwa is ready. Serve hot with sprinkled nuts or seeds.