Braising fish in a pot and then burying the pot in hot ash is a common cooking technique in northern Vietnam. However, in Lai Châu province, the ethnic Thái community has a rather primitive way of cooking. They wrap fish in a leaf, and then cook them in hot ash. The mild aroma of the green leaf makes the fish tastier, and the dish is a delicacy in the region.
The fish used in this dish is a small freshwater goby species in the genus Rhinogobius, caught in the mountain streams in northwest Vietnam. The species name could be Rhinogobius duospilus, however in Vietnam there are also other spieces of the same genus such as Rhinogobius giurinus or Rhinogobius leavelli. The local name for the fish is “cá bống suối”, which literally means “stream goby“.
The cooking method can be summerized like this: First, the stream goby fish are marinated with local spices including lemongrass, chili, ginger, black pepper, mắc khén pepper (Zanthoxylum rhetsa), basil leaves, and a different wild basil leaves. The fish then get wrapped in lá dong leaves (Stachyphrynium placentarium), and finally get cooked in hot ash.
Rinse the stream gobies with brine water to remove the fish smell. Marinate the fish with all the prepared spices for 15-30 mins
Wrap the fish in a big leaf. The leaf should not be too young or too old, and should not have holes or cracks.
Bury the fish wrap in hot ash. Flip the wrap every 30 mins until the fish are cooked.
Serve with hot rice, sticky rice, or adjust the saltiness to serve as a drinking food.