Maccher Jhol (Fish In Bengali Sauce)

Ingredients

• 800 gms white-fleshed fish
• 1/2 tsp ground turmeric
• 1/2 tsp salt
• 2/3 mustard oil or vegetable oil
• 1 tbsp ground coriander seeds
• 1 tsp ground cumin seeds
• 1 1/2 tsp finely grated ginger
• 1 tsp ground turmeric
• 1/2 tsp red chilli powder
• 1/4 tsp kalonji
• 4 whole red chillies dried
• 2 bay leaves
• 1 large onion peeled, chopped
• 3 whole green chillies