Soak the golf size fresh tamarind in 3 tbsp warm water for 5 minutes and squeeze the tamarind juice out of it. Discard the skin.
Pour the tamarind juice into the clay pot, add enough water (1 cup water) to thin down the gravy and give it a stir.
Now, add the cleaned fish and curry leaves into the curry or gravy, cover the clay pot with a lid and let come to a boil. Make sure to lower the heat.
Taste the curry and add more salt if needed.
When the curry has come to a boil and the fish cooked well, remove the clay pot from the heat, cover it and let cool down for sometime.
This fish curry goes well with rice, pathiris, and chapatis.
Notes
You could adjust the spice level according to your needs. The more the spice the more tastier this fish curry gets. You could also store the ground paste in the refrigerator for few days. This fish curry tastes better the next day.
Recipe by Cooking with Thas - Healthy Recipes, Instant pot, Videos by Thasneen at https://www.thasneen.com/cooking/spicy-fish-curry-made-in-the-clay-pot/