Take a pot, fill it with water and add the bananas (single piece separately).
Bring it to boil for 15 - 20 minutes.
Once you see the banana losing its colour, turn off the gas and keep it aside.
Once it is cooled completely, peel and chop into cubes evenly.
In a pan, take coconut oil; add jeera, mustard seeds, onions, garlic, ginger, turmeric, and red chilli paste.
Let it cook for 10 minutes.
Now, stir in the chopped bananas; add coconut milk and tamarind paste.
Cover it with the lid, and let it cook well on a slow flame for 5 to 6 minutes.
Add coriander, basil, and salt as per taste.
Serve hot with rice or roti.
Variations:
If the gravy looks too thin, add some sattu flour mixed with water.
Add other vegetables along with the banana for more flavour.