In a small pan, heat ½ tsp of oil and fry all the ingredients mentioned under 'roast and grind' until aromatic.
Let it cool down and then grind it to a smooth powder.
Soak the tamarind in about 2 cups of hot water and extract the juice. If needed, add one more cup of hot water and extract that water as well.
In a heavy bottom pan, heat 1 TBSP of oil and fry the sundakkai / turkey berry until dark brown. Make sure that you fry it with enough ventilation and in low heat to avoid burning and excessive smoking.
Remove the turkey berry into a bowl.
In the same pan, heat the rest of the oil. Add the mustard seeds, toor dal, red chilies and asafetida and let it fry.
Add the chopped murungakkai / drumstick and cook it for about 3 to 4 minutes.
Pour the extracted tamarind water to the pan along with turmeric powder and salt needed.
Let the kuzhambu come to a boil and then add the curry leaves. Simmer the kuzhambu for about 10 minutes or until the raw smell of the tamarind disappears and the vegetable cooks.
Dissolve the ground powder in water and add this to the boiling kuzhambu. Make sure you dissolve the powder in water otherwise it will clump up in the kuzhambu.
Let this boil for another 7 to 8 minutes. You will notice that the kuzhambu will thicken after we add the ground paste.
At the end add the fried sundakkai vathal / turkey berry to the kuzhambu and let it boil once more. Turn off the flame and serve it with hot rice and ghee / nei.