Wash the bittergourd well. Cut it into two lengthwise. Remove the white portion with seeds from the bittergourd.
Then scrape the outer skin with knife. Chop the bittergourd into small pieces.
In a bowl take one small ladle of curd and water. Add the chopped bittergourd into the curd mixture. Soak it for 20 minutes. This helps to get rid of the bitterness.
Meanwhile extract juice from tamarind. Add water into the tamarind, boil it for two minutes and extract juice from it. Keep it aside.
In a pan or kadai add coconut oil or gingelley oil. Add mustard seeds and splutter them. Once they crackle, add urad dhal, curry leaves, asafoetida and saute until the dhal turn golden brown.
Now drain the bittergourd from the curd mixture and add into the kadai. Close it with the lid and cook until its half done.
Then add the tamarind extract, turmeric powder, salt, jaggery and mix well. Once again close the lid and cook.
The colour of the bittergourd will turn from green to light brown. Also the gravy starts thickening.
Finally add the Mangalore rasam podi and mix well. Cook for five more minutes. At this stage the mixture would have thickened. Turn off the stove, allow to cool and store it in refrigerator for 3 to 4 days.
You can mix it with rice and serve with papad or as an accompaniment for curd rice.