Mix Corn Flour in Water and keep aside. To a heavy bottomed pan, add Caster Sugar and caramelize. Reduce the flame and add the cornflour-mixed water.
Do not stop stirring at any time. Once the mixture starts to thicken, add Cashew Nuts, Butter, Saffron Threads, Ground Cardamom, and Rose Water. Let the mixture become thick and until starts to leave the sides of the pan.
Now switch off the flame. You might feel that the halwa is not at all solidified, but as it gets cool it will thicken. This halwa is not the type of halwa to cut and serve in pieces. This halwa is eaten with a spoon.