Among all catfish types in Vietnam, bagrids (those in the familiy Bagridae) are the most prized ones because of its firm meat texture and aroma. Most Vietnamese bagrids belong to the genus Hemibagrus. Before 1975, bagrids are unknown to southern Vietnam. Only in 2000s, bagrids occurs in the menu of some restaurants in Saigon. In Hanoi, a popular dish Chả cá Lã Vọng or Chả cá Thăng Long is made of bagrids.
Green bananas are used in this braise dish to add the acrid taste, and cowa mangosteens are source of acidity. Other ingredients include: pork belly, tumeric, green tea juice. Overall, the dish will emcompass a full-taste palate.
Coat a clay pot with a layer of galangal and ginger slices, dried cowa, and place the fish pieces on top. Pour hot green tea water into the pot, so the fish pieces are submerged. Bring the pot to a boil, and skim off foams. Reduce the heat until the water dries up. Add black pepper, and green onion leaves.
Using green tea with fish stock helps deodorize and make braised fish more delicious.
Laying galangal and green tea leaves at the bottom of the pot prevents the fish from getting sticked to the bottom.