Grind the chopped onion and make a coarse paste. Keep it aside.
Cut the fish in a medium size and marinate the fish with lemon juice and salt. Cover it and keep it aside for 5-6 min.
Add all marination ingredients, mix it well. Keep it for 15 minutes.
Line the baking tray with aluminium foil and grease some oil on top of the tray. Preheat the oven in broil mode. Place the marinated fish in baking tray.
Bake it for 15 to 25 minutes till it gets golden color from all sides by flipping.
In meanwhile, Heat 3 tbsp oil in a deep pan. Add grind onion, garlic- ginger paste and little salt, saute it till golden color.
Add coriander powder, cumin powder, pepper powder, turmeric powder, amchoor powder, mustard powder and Kashmiri red chili powder. Add 2 tbsp water and saute it for 2 minutes.
Add 2 cup of water and let it boil.
Once it start boiling, add grilled fish and cook for 10 minutes at medium heat.
Salmon fish curry is ready to be served. Serve it hot with rice and fulka.