Wash and clean fish thoroughly with turmeric powder and salt.
Marinate fish with red chilly powder and salt.
Peel some pearl onions, chop a medium sized tomato. Take a tsp of Channa dal and Urud dal.
Dry roast the above ingredients along with 2tbsp of grated coconut.
In a kadai, add oil and mustard seeds. Once it splutter's, add the grinded mixture. Bring it to boil. Then add the marinated fish pieces and leave it in simmer for 6-8mins.