For marinating the fish:
Fish – 1 lb, cut into small pieces
Turmeric powder – 1/4 tsp
Red chili powder – 1/2 tsp
Salt – 1/4 tsp
For the curry,
Oil – 2 tbsp
Red onion – 1 small, roughly chopped
Ginger – a 1 inch piece
Garlic – 3-4 pods
Green chilies – 4
Red chili powder – 1 tbsp
Coriander powder – 1 tbsp
Turmeric powder – 1/2 tsp
Tamarind – a small lime-sized ball (or tamarind paste – 2 tsp)
Water – 1/2 cup
Coconut milk – 2 cups
Salt – to taste
Oil – 2 tsp
Mustard seeds – 1/2 tsp
Ginger – a small piece, julienned or finely chopped
Garlic – 1-2 pods, thinly sliced
Curry leaves – a few
Wash the fish pieces and marinate with the ingredients listed under “For marinating the fish”. Keep aside while the curry/sauce base is prepared.
Prep the following. Coarsely grind the onion, ginger, garlic and 2 green chilies. Make a paste of red chili, coriander and turmeric powders in 2 tbsp water. Soak the tamarind in 1/2 cup of hot water, extract the pulp when the water is comfortable enough to handle. Keep all these on hand before starting on the curry.
To prepare the curry, heat oil in a pan. Add the ground onion mixture and saute on medium heat till the raw smell goes and it turns a light golden color. Add the paste of masala powders and saute for 2 minutes. Add the strained tamarind pulp water and allow it to come to a boil.
Add the coconut milk and bring to a gentle boil. Now add the fish pieces, 2 chopped green chilies and salt and cook without covering the pan for a few minutes. Fish cooks extremely fast and is very delicate, so do not cover the pan or stir the curry.
Once the fish is cooked (it will be opaque and flaky), increase the heat and reduce the curry to the desired consistency. Coconut milk curry will further thicken upon standing, so remove it from the stove just short of your desired consistency.
In a small pan, heat the oil for tempering. Add mustard seeds and when they sputter, add the rest of the ingredients and fry till the ginger and garlic are lightly golden (but not burnt). Add this to the prepared curry and mix well. Allow the curry to rest for a while before serving, as this will help the flavors to develop beautifully.
Use a well-seasoned earthen pot to cook and serve fish curry in, as it really helps to develop the flavor and aroma.
You can use 2 cups of water to cook the fish and then finish the curry with a tiny splash of coconut milk. This way, the curry will be more red in color than one prepared fully with coconut milk. It will also be spicier, so use more water and less of coconut milk if you love a spicy fish curry.
In some regions, the tamarind is replaced with pieces of kudam-puli, the preserved dried fruits of Garcinia Cambogia, which imparts a distinct sour and smoky flavor to the fish curry.
Serve warm fish curry with steamed white rice or any Indian flat bread like appams, dosas, chapathis or rotis.