"In this Pinoy fish recipe, mackerel is first simmered in a tangy tamarind base and then fried. It is important that the fish is fresh. Instead of frying, you can also wrap the fish in banana leaves and grill it. Serve with mango relish."
Combine the mackerel, water, tamarind soup base, and fish sauce in a pot over medium heat. Cover and cook at a simmer for about 15 minutes. Flip the fish, cover again, and simmer another 15 minutes. Remove from heat and allow to sit, covered, for 1 hour.
Heat oil in a deep-fryer or large saucepan to 350 degrees F (175 degrees C). Remove the fish from the pot and pat dry with paper towels to remove as much excess moisture as possible.
Fry the fish in the hot oil until golden brown, 7 to 10 minutes. Serve hot.