Wash the mint leaves and divide into three portions as mentioned above.
Mix the 1 tbsp of tamarind paste with 1 cup of water and set aside.
Add the tamarind water, ⅔ cup of mint leaves, washed and soaked masoor dal, chopped tomato, salt, hing, jaggery, ground pepper and rasam powder directly to the instant pot.
Then add 2 cups of water.
Mix them thoroughly and cook this rasam mix in manual mode for 10 minutes and release the pressure naturally.
Once the pressure is released, open the IP lid and then set the IP in saute mode.
Mash the rasam mix nicely so that the dal blends well.
Add half more cup of water and ⅓ cup of mint leaves minus 1 tbsp and let it simmer for 5 minutes.
Meanwhile, do the tempering separately over stop top. Heat the tempering pan or kadai and add oil. Once the oil is hot, add the mustard seeds, cumin seeds, and mint leaves and as the mustard seeds start to splutter, add it to the rasam.
Turn the IP off, and that's it. Mint rasam with masoor dal is ready.
Pressure cooker method:
In a pressure pan or hundi type pressure cooker, add the tamarind water, 2 cups of water, ⅔ cup of mint leaves, washed and soaked masoor dal, chopped tomato, salt, hing, jaggery, ground pepper and rasam powder and pressure cook for two whistles.
Once the pressure is gone, add required water and remaining mint leaves and simmer the rasam.
Finally, do the tempering.
You can add more water as per your preference. I prefer slightly thick consistency for mint rasam so went only with 3.5 cups of water, and that includes the tamarind water too.
Adjust the salt and spices as per your preference.
Instead of masoor dal, you can use toor dal too.
To make it a one-pot dish, you can do the tempering first on the IP in the saute mode and then add all the ingredients.
I loaded this rasam with mint leaves, and I am adding it in three stages. Also, I did not add, curry leaves or cilantro for this and went only with mint flavor.