The moonfish, Mene maculata, is the only extant member of the genus Mene and of the family Menidae. This marine fish is native to the Indian Ocean and Western Pacific. It is easily recognized by its round flat body, which some may relate to the moon. In Vietnam, the moonfish occurs in some provinces in the central coast. Its shape is compared to the axe, or the propeller, which gives it some Vietnamese names like cá lưỡi búa, cá liệt búa (lit. means axe fish or hatchet fish), cá bánh lái (lit. means propeller fish).
The moonfish can be cooked by braising with chili peppers, black peppers and fish sauce. But a more popular choice in Vietnam is to make the moonfish sour soup. The main acidity source of this fish soup is from tamarind leaves and/or tamarind fruits. In central Vietnamese cookery, the moonfish is often cured with chive bulbs (Allium schoenoprasum) to remove the fishy smell.
Clean the moonfish, and rinse optionally with rice wine and crushed ginger. Marinate the fish with some salt, fish sauce, pounded chive bulbs, and turmeric powder, for about 30 mins.
In a pot, heat some oil, saute some minced shallots and chili. Add the marinated fish and get them sauteed until their flesh stiffens.
Add water to the pot, and bring to a boil. Add tomato wedges, and bring to a boil again. Add the tamarind leaves, re-season to taste and turn off the heat.
Prepare a small bowl of dipping sauce with pounded chili. Serve with hot rice.
In Vietnam, tamarind leaves can be replaced with the leaves of June plum plant (Spondias dulcis), or la giang (Aganonerion polymorphum). Fresh or ripe tamarinds, or tamarind paste can also be used as an alternative.
The moonfish sour soup can also be cooked with Southern style with pineapple, tomatoes, Colocasia gigantea stalks, sugar...