Heat mustard oil in a pan and add mustard seeds. Once they splutter, add sliced onions and sauté until golden brown.
Add ginger-garlic paste and green chilies. Sauté for a minute.
Add turmeric powder, cumin powder, coriander powder, red chili powder, and salt. Mix well.
Add chopped tomatoes and cook until they turn soft and the oil starts to separate.
Add water to make a gravy consistency. Bring it to a boil.
Gently add the fish pieces to the gravy. Cover and cook on low heat for about 10-15 minutes or until the fish is cooked through.
Garnish with fresh coriander leaves.
Serve hot with steamed rice or bread.
Enjoy!
