In a pressure cooker add Sweet potato and cook for 3 whistles. Soak Saffron in luke warm milk and set aside.
Once the pressure is released, allow the sweet potato to cool down completely. Peel the skin and mash it really well such that no lumps remains.
Heat 2 tbsp ghee in a pan add cashew nuts and Almonds. Fry till they are golden and set aside.
In the same pan add cooked and mashed sweet potato. Allow it to cook for 5 mins in a low flame.
Next add sugar. The sugar starts melting , keep cooking in low flame.
And then add saffron soaked milk. Mix well and cook the halwa. It will have a gooey consistency at this stage
Next add cardamom powder combine everything together.
Now add 1 tbsp of ghee at a time and stir and cook the halwa.
Add the remaining ghee and keep cooking till the halwa leaves the sides of the pan.
Finally add ghee fried nuts combine everything and switch off. Sweet Potato halwa is now ready.
Notes
Adjust the amount of sugar as per your taste as the sweet potato already have the natural sweetness.The halwa gets cooked very fast as the sweet potato are already cooked. So cook in a low flame to avoid getting burnt.You can definitely use more ghee if you prefer.You can also make sweet potato halwa with condensed milk as an alternate to sugar. If using use ½ cup of condensed milk.sweet potato halwa with jaggery also has the similar texture but may have a slightly different color.Make sure you stir constantly towards the end to prevent the halwa from getting burnt.