Prep the Fish:
Rinse the fish fillets, pat them dry with paper towels, and cut them into large chunks. Season lightly with salt and set aside.

Heat the Oil:
In a large skillet or pot, heat the vegetable oil over medium heat. Add the mustard seeds (if using) and let them pop for 20-30 seconds.

Cook the Aromatics:
Add the chopped onion and sauté for 3-4 minutes until soft and translucent. Stir in the garlic, ginger, and green chilies (if using) and cook for another minute.

Add Spices:
Sprinkle in the turmeric, curry powder, and ground coriander. Stir for 30 seconds to toast the spices and enhance their flavor.

Build the Base:
Add the chopped tomato (or tomato paste) and cook for 2-3 minutes until it softens and forms a thick paste with the spices. If using tamarind paste, stir it in now.

Add Liquids:
Pour in the coconut milk and water (or fish stock). Stir well to combine, then bring the mixture to a gentle simmer. Season with salt and pepper.

Cook the Fish:
Carefully add the fish chunks to the curry, ensuring they’re submerged in the sauce. Simmer gently for 8-10 minutes, uncovered, until the fish is cooked through and flakes easily. Avoid stirring too much to prevent breaking the fish apart.

Taste and Adjust:
Taste the curry and adjust seasoning with more salt, pepper, or a squeeze of lemon juice if you didn’t use tamarind.

Serve:
Garnish with fresh coriander and serve hot with steamed rice or ugali

TIP
Fish Choice: Use firm fish that holds up well in curry, like cod, haddock, or snapper. Avoid delicate fish like sole, which may disintegrate.

Spice Level: Adjust the chilies and curry powder to your taste. For a milder curry, skip the chilies.

Time Saver: Pre-chopped onions or canned tomatoes can cut prep time slightly.