Kallumakkaya or kadukka or kakka in some place are shellfish called Mussel.
Clean the Kallumakkaya properly and take the flush from shell.
For taking, flush, first boil the kallumakaaya in water for 5 minutes. Once it is cooled it will open the shell, then you can easily take the flush using knife.
In a bowl add cleaned kallumakaaya pieces, 1/4 tbs of salt, 1 tbs red chili powder, 1/2 tbs turmeric powder, 1/2 tbs pepper powder and 1 tbs of cornflour into it. Marinate with ingredients and keep aside for at least 10 minutes.
Then shallow fry the kallumakaaya in oil and keep it aside.
In this oil( we fried the kallumakaaya) add 1 tbs ginger, 1 tbs garlic paste, and chopped green chilies . Saute it and add chopped onion into it. Add 1/2 tbs of salt now and stir it well.once onions turn it color to golden brown add chopped tomatoes into it. Mix it well and cook the tomatoes. After 3 to 4 minutes add fried kallumakaaya into it. cook for 2 minutes. Then add 1/2 tbs of red chili powder, 1/2 tbs of turmeric powder, 1/2 tbs of pepper powder,1/2 tbs garam masala and 2 tbs of tomato sauce. Stir it well and cook for 3 to 4 minutes.
Finally add add coriander leaves.
Tasty kallumakaya roast ready to serve. Serve with rice, chapati , pathiri, appam etc…