Clean and wash the mussels nicely.
Cook the mussels in water with red chilly powder, turmeric powder, garam masala and salt as required.
In a pan heat oil, put the chopped onion and saute well. Add ginger garlic paste, green chillies and saute well for 5 more minutes. Add chopped coriander leaves, curry leaves and stir in the cooked kallumakkai. Mix well and remove from flame. Keep aside.
Meanwhile, mix rice flour with salt and water as required, knead the dough well. Take small balls out of this dough and make small discs by rolling out. Keep a small amount of the prepared kallumakkai filling in this ada, close it and roll into a idli shape.
Take an idli maker, rub oil on idli plates and place the masala filled balls into the idli moulds. Press to get the correct idli shape. Switch on the flame and steam with covered lid for 20-25 minutes.
Remove the cooked adas from the idli makers and serve hot. Idli Shaped Kallumakkai Ada is ready.