Heat the oil in a large pot over medium heat; saute the onion for about 5-7 minutes, until softened then add the garlic and saute for a few seconds more.

Add the salt, pepper, cayenne pepper, turmeric, garam masala, curry powder, and cumin, chicken broth, coconut milk, lemon juice, tamarind paste and cilantro.

Bring to a simmer then reduce heat to low and add the fish, being careful not to over-stir (the fish will break apart). Cook for 10-15 minutes, stirring occasionally (very carefully) until the fish is cooked through. Serve over basmati rice.