Wash beetroots under running water. Peel the skin and grate them. A food processor eases the job of grating. You can also grate with a hand held grater.
Heat a pan with ghee. Fry cashew nuts until golden and crunchy. Remove to a plate and keep aside.
To the same pan, add beetroot and fry until it turns aromatic for about 3 to 4 minutes.
Reduce the flame. Pour 1½ cups milk or condensed milk + ¼ cup milk as per your choice.
Give a good stir and cook covered for a 3 to 4 minutes on the lowest heat. This helps the beets to release all of the moisture.
Open the lid and simmer until most of the liquid evaporates and the halwa turns thick. Beets should be softened by now.
Add sugar and cardamom powder. Make sure the beetroot is soft cooked before adding sugar. Sugar melts and moisture is released making the halwa gooey again.
Cook till the moisture evaporates. If you prefer a dry halwa, continue to cook further.
Transfer beetroot halwa to serving bowls and garnish with nuts. Best served chilled during summers and warm during winters.