Step 1

In a small bowl, combine Malabar tamarinds with enough hot water to cover and set aside for 15–20 minutes to soften.

Step 2

With measured spices nearby, heat 2 Tbsp oil in a medium frying pan over medium-high heat, until oil is shimmering. (To test the heat, add a couple of mustard seeds. If they start to sizzle, the oil is ready.) Reduce heat to medium, add mustard seeds, and crackle them for just a few seconds until popping subsides, taking care they don’t burn. Immediately add coriander and cumin seeds and roast for a few seconds. Add chili powders and turmeric and cook for 30 seconds, until the smell of raw spice disappears. Add coconut and stir for 2 minutes, until warm and lightly colored.

Step 3

Add contents of the pan to a food processor. Blend, adding enough water (about 1/4–1/2 cup) to make a smooth, thick paste. Set aside.

Step 4

Heat the remaining 1/4 cup oil in a large frying pan or wok over medium-high heat. Add curry leaves, green chile, onions, ginger, and garlic and sauté for 1 minute. Stir in the reserved coconut paste, then add tomatoes and soaked Malabar tamarinds with the soaking liquid. Boil for 5 minutes, then season with salt.

Step 5

Add fish, reduce heat to medium-low, and simmer for 5 minutes, or until just cooked. Transfer to a serving platter. Garnish with cilantro and serve, if you wish, with neer dosa and ginger pickle.