Marinade the fish steaks with a little salt. Heat oil in a pan, shallow fry the fish steaks.
Allow them to cool enough to handle. Mash roughly, deboning the fish steaks carefully. Keep aside.
Pre-heat the oven to 180C.
Soak both the mustard seeds in warm water for 15 odd minutes. Drain from water, make a smooth paste along with two green chilies and a pinch of salt.
Whip two eggs in a bowl with a little salt.
Take the deboned fish steaks in a mixing bowl, add the onion paste, ginger paste, mustard paste, chopped onions, green chilies, coriander leaves, breadcrumbs, black pepper powder, whipped eggs, ghee, tomato sauce and vinegar. Give it all a hearty mix.
Grease the baking mould generously with ghee, add the fish mix. Level with back of a spoon.
Bake for 20 minutes. Serve hot.