“Canh chua” (literally "sour soup") is indigenous to the Mekong Delta region but has spreaded widely to other part of the country. It is typically made with fish from fresh water, pineapple, tomatoes, and sometimes other vegetables such as okra or peppermint, and bean sprouts, in a tamarind-flavored broth. Canh chua is garnished with the lemony-scented herb “ngò ôm” (Limnophila aromatica), caramelized garlic, and chopped scallions, as well as other herbs to lessen the strong flavour of fresh fish. Depending on the specific variety of “canh chua"; these other herbs may include” rau răm” (Vietnamese coriander), “ngò gai “(long coriander), and” rau quế” (Thai basil).
The sour taste of the soup can come from various sources such as pickled vegetables, fresh fruits like tamarind, sour leaves or vinegar. They are mixed with a small amount of hot water; the mixture is then stirred for a few moments to release all the essence, and the liquid (minus the fruit seeds and other solids, which are discarded) is then added to the soup.
There are many types of “canh chua” but the idea are similar. Some Canh chua can include baby clams or ribs instead of fish or meat balls. Canh chua is best served cool during the over-heated summer of Vietnam.
Indian taro cooked with mullet (Canh dọc mùng nấu cá quả)
In preparation stage, we choose required ingredients including: mullet, a bunch of Indian taro, tomatoes, onion, red chilli, tamarind, dill, a spoonful vinegar, “nước mắm”, salt and pepper. Fish is washed carefully with salt water and vinegar then chopped into several small chunks. Indian taro is peeled, carefully washed, sliced into small pieces, soaked in salt water for 30 minutes and then pressed to remove resin. Tamarind is peeled and thinly sliced.
Firstly, fish is fried until its colour changes into yellow. Afterwards, we mash spring onion and chilli together using a mortar and pestle or blend them with a blender. Then we heat oil and stir fry mashed spring onion and chilli mixture in the pot until fragrant. After that, we add slices of tomatoes, a little “nước mắm” and cook until fragrant and soft. In the next step, we add fried fish and a desirable amount of water into the pot. Tamarind is then added. If you want more sour taste, you can always add some vinegar later.
The deep skillet is boiled for 30 minutes, until bubbly before Indian taro is added. Finally, we add dill and green onion to garnish. This type of canh chua is best served with fresh lettuce or steamed rice.