Dien dien (Sesbania sesban) is a yellow flower found in the Mekong Delta during flooding season. This kind of flower is a secret ingredient for local sour soup, which makes it a lot tastier.

Sour soup in the Mekong Delta as well as other localities commonly includes Indian taro (Colocasia gigantean), okra, ngo om (Limnophila aromatica), to name but a few. Dien dien flowers are a highlight of Mekong Delta’s sour soup. Adding these flowers into a hot pot of sour soup is the final step in making the dish. That will help maintain the unique flavor of the tiny yellow flowers, according to local cooks. Loyal to the traditional recipe of sour soup, the sour taste is from tamarind, pineapple and tomato. Yet don’t forget to add a little sugar. Slices of red tilapia will be lightly fried before being put into the soup. A bowl of sour soup has eye-catching colors: the yellow of dien dien flower, the green of okra and ngo om, and the red of chili. The dish must be served with hot rice and fish sauce. A dish of salad with sesame sauce may be a side dish that well matches the sour soup.

By Anh Quynh