Cook the plantain in water with the turmeric powder and jaggery till it becomes soft.
Drain the plantains out from the water with a slotted ladle. Heat the ghee in a sauté pan and sauté the plantains in the ghee for a couple of minutes. Reserve the water in the other pan.
Grind the ingredients under "grind to a paste" to a smooth paste.
Add this to the reserved water and simmer on low heat. Add the plantains back to this sauce mixture and let it simmer for 2-3 mins on low heat.
Heat the oil for tempering in the saute pan. Add the mustard seeds. Once they splutter, add the curry leaves and chillies and pour into the plantain with the sauce. Mix well and serve with rice!