Coat fish with ground turmeric. Season with salt. Marinate for 30 minutes in the refrigerator.

Heat 1 tablespoon oil in a large frying pan. Add fish. When one side is browned, flip over to brown the other side. Drain on an absorbent paper towel. Set aside.

Marinate potatoes and eggplants (if using) with ground turmeric. Season with salt.

Add potatoes to the same pan used for frying fish. Shallow fry until both sides are brown. Drain on an absorbent paper towel. Set aside.

If you are using eggplants, fry eggplants and set aside.

Place onions in a food processor. Grind to a smooth paste. Set aside.

Heat oil in a large frying pan over medium-high heat. Add cumin seeds, bay leaf and cardamom pods. Sauté, stirring constantly, for a minute or until fragrant. Add onion. Sauté, stirring occasionally, for 1-2 minutes or until slightly browned.

Add ginger, garlic and green chilies. Sauté, stirring occasionally, for 1-2 minutes or until fragrant. Add tomato paste. Sauté, stirring occasionally, for 1 minute.

Add ground turmeric and ground coriander. Sauté, stirring, for a minute or until fragrant. Add yogurt. Stir to combine. Simmer 2-3 minutes or until oil separates.

Stir in potatoes and eggplants (if using). Pour water. Stir to combine. Cook, covered, for 2-3 minutes or until potatoes are tender. Add fried fish. Stir gently. Cook, covered, for 5 minutes or until fish is cooked through and sauce is slightly thickened.