Coarsely mince garlic and fry till golden brown. Remove from oil and drain on paper towel. Save oil and set aside.
Marinade the prawns/fish with the fish sauce and pepper.
In large pot, using the oil from the garlic, saute the shallot. If using shrimp skip ahead to next sentence. If using fish steaks, quickly sear in the hot oil, flipping once. Add water/stock and tamarind, vinegar, sugar and bring to boil. Then add tomatoes, pineapple, okra, shrimp.
When prawns are cooked and tomatoes are just tender, add bean sprouts and taro stems and season with additional salt or fish salt and sugar to taste. It should be sweet, sour, and savory.
Remove from heat finish with rice patty herb, fried garlic and optional chili. If using fish steaks, remove fish and place on clean plate. Season with fish sauce and chili. Serve the plate of fish as a side and serve immediately with white rice.