Wash, peel, and chop the beetroot. Grind it with added water until smooth. Strain the mixture using a cloth or fine strainer and extract the juice. Measure 2 cups (approximately 400ml) beetroot juice and keep aside.
Beetroot Juice Prep : The star ingredient, You will need about 1 cup of fresh juice. Grate fresh raw beetroots and squeeze them to extract the juice. Tip: Do not boil the beets first; raw juice gives the best vibrant color and setting property.
In a pan, add jaggery and ½ cup water. Heat until the jaggery melts completely. Switch off the flame, filter the syrup to remove impurities, and allow it to cool.
Corn Flour (Corn Starch) : This is the binding agent that gives the halwa its glossy, jelly-like texture.Important Note: Ensure you are using white corn starch (often labeled as Corn Flour in India). Do not use yellow maize flour or makki ka atta, as the texture will not set. In a mixing bowl, add corn flour. Slowly pour in the beetroot juice and the cooled jaggery syrup. Mix well using a whisk or spoon until smooth and completely lump-free. Keep this mixture aside.
Heat a heavy-bottomed pan and add 2 tbsp ghee. Add the chopped nuts and roast until lightly golden. Remove the nuts and keep aside.
In the same pan, add 1 tbsp ghee and pour in the prepared beetroot mixture.
Cook on medium flame, stirring continuously. At first, the mixture will be watery. Keep stirring and scraping the bottom and sides to prevent sticking.
As the mixture begins to thicken, add 1 tbsp ghee at a time, mixing well after each addition. Continue stirring continuously. You will gradually use 6 to 8 tbsp ghee in total during this stage.
When the halwa becomes glossy, thick, and starts leaving the sides of the pan, add the roasted nuts and cardamom powder.
Continue cooking until the halwa comes together as a soft mass, with no raw smell of corn flour and a shiny finish.
Transfer the hot halwa into a greased tray or plate. Level the top using a spatula.
Allow it to set for at least 4 hours at room temperature. Once set, cut into pieces and serve.
