Peel green plantains,wash them. Cut them into 1/2 inch circular pieces.put aside.
For masala paste : take a blender jar ,add chopped onion,ginger,garlic,coriander seeds,cumin seeds,green chillies and grind to a fine paste,adding water as needed.
Take a non stick kadai, put the cut green plantain pieces,all of the masala paste,red chilli powder,turmeric powder,salt,2 to 3 tbsp of water. Put the kadai on medium flame,without lid,for 7 to 8 min ,until the water evaporates,and plantain pieces are soft,with masala paste well coated to them.
Take another shallow non stick pan, put enough to shallow fry the plantain pieces ,add curry leaves,fry for about 10 minutes on a medium flame, until brown.
Serve hot as a snack or with rice and rasam.