Fish Sinigang (Tilapia) - Filipino Sour Broth Dish

In a medium pot, combine the tilapia, bok choy, tomatoes and radish. Stir together the tamarind paste and water; pour into the pot. Toss in the chili peppers if using. Bring to a boil, and cook for 5 minutes, or just until the fish is cooked through. Even frozen fish will cook in less than 10 minutes. Do not over cook or else the fish will fall apart. Ladle into bowls to serve.