Trim the ends of the Murungakkai or drumstick and cut each one into 2 or 3 long pieces.
Heat a pan with 1 to 2 cups water. When it comes to a boil, add drumstick pieces, tamarind, turmeric powder, 2 pinch salt.
Let it cook over medium flame till the drumstick become soft.
Once cooled drain away excess water, discard the tamarind and remove the drumstick pieces on to a plate.
Open the drumstick and using a spoon scrape away the pulp along with the seeds and keep it aside.
Heat a pan with oil. Add mustard seeds and let it splutter.
Add urad dal and roast till it becomes golden in color.
Add onion, curry leaves and sauté till the onion turns translucent.
Add the murungakkai pulp, red chili powder, sambar powder, salt and mix well.
Let it cook for another 3-4 minutes over low flame for the flavors to merge together.
Murungakkai thokku is ready to serve.
You can either serve this as a side dish with sambar or rasam rice or mix this thokku with rice and eat.