Heat a dry pan and when hot, add curry leaves and roast till it loses its moisture for 2-3 mins tossing frequently over medium heat till the aroma arises.
Transfer to a plate to cool down.
In the same pan heat the oil. Add urad dal, coriander seeds, whole dry red chilies, peppercorn, fenugreek, and roast till they all become golden in color taking care not to burn them. Drain and keep aside
Add the tamarind and roast for about 2 mins over low flame for it to lose its moisture. It will become slightly crisp.
In a dry mixie jar add the roasted spices and curry leaves and run for a minute till it is coarse.
Add the tamarind piece and run for another minute.
Add a little water and grind to a fine paste and keep aside.
Heat 3 tbsp of ghee or oil in a pan and roast the halved cashew nuts. Drain and set aside.
Now add mustard seeds, when they splutter add cumin seeds, urad dal, whole red chilies and sauté for a minute.
Now add the ground spice paste, turmeric powder, salt and mix well.
Sauté for 2 minutes over low flame for the raw smell to go away.
Add cooked rice, roasted cashew nuts and mix well.
Karuveppilai Sadam is ready to be served or to be packed in a lunch box.