Mince the onion, ginger and garlic together. Steam the fish. Remove the skin & the bones and Mash them. Add the onion-ginger-garlic mixture, breadcrumbs, garam masala, well-beaten eggs, salt and cumin powder to the fish. Mix well to make a homogeneous mixture. Make lemons sized balls out of the mixture and flatten them into thick patties.
Heat 2 tbs of oil in a shallow frying pan and fry few at a time until both sides become golden brown (turn it once). Repeat this until all the patties are fried (Pour some oil every time you replace them). Serve hot.