Kaeng som kung dok khae is a version with shrimps and dok khae, the flowers of the Sesbania grandiflora
A traditional and basic kaeng lueang pla/kaeng som pla from Southern Thailand
Kaeng som or gaeng som (Thai: แกงส้ม, pronounced [kɛ̄ːŋ sôm]) or Thai sour curry is a sour and spicy fish curry or soup with vegetables popular in central Thailand. The curry is characteristic for its sour taste, which comes from tamarind (makham). The recipe uses palm sugar (Thai: น้ำตาลปี๊บ, namtan pip) to sweeten the curry.
A paste called nam phrik kaeng som is prepared as a base for the curry, to which water and the ingredients are added. The preparation of this paste includes shrimp paste and shallots and all the ingredients are pounded with a mortar and pestle. This paste can be made from dry red chilies and one made from fresh red chilies. Some recipes state that large chilies should be used, others prefer bird's eye chilies.
Fish or shrimp may be used as the basic ingredient. Preferred fish are those that keep their consistency after boiling, such as Channa striata or other equivalent marine fish in coastal locations. One variant uses fish eggs.Kaeng som is usually served with steamed rice.
Traditional vegetables used in household preparation include drumstick pods (marum), green papaya, and Sesbania grandiflora flowers (dok khae), including the red variant of the flower in kaeng som dok khae daeng. Other locally available vegetables are used in the traditional versions such as Ipomoea aquatica (phak bung) and Neptunia oleracea (phak krachet).
The versions using shrimp instead of fish are more popular; kaeng som with shrimp and cha-om omelet is now a standard dish in Thailand. Other types may include pineapple or seafood. The common point, however, is that coconut milk is not used in this sour curry.
Southern Thailand has its own sour curry, which is locally called kaeng som, but in the rest of Thailand is called kaeng lueang ("yellow curry") or kaeng som phak tai ("southern Thai kaeng som") to differentiate it from the central Thai kaeng som. It differs from the central Thai dish through its use of assam fruit (som kaek) to achieve the sourness, turmeric, which gives it a yellow color, garlic instead of shallots, and sugar isn't added as in the Central version. Depending on the cook, tamarind or lime juice may be used instead of assam fruit to achieve sourness, but the main characteristics of the southern variant is the use of turmeric and that it isn't sweet.
In Kelantan, the Malaysian state adjacent to Thailand, the Kelantanese-Thai dish 'kaeng som no mai dong is a version of kaeng som with pickled bamboo.
^Sanitchat, Jam. The Everything Thai Cookbook Includes Red Curry with Pork and Pineapple, Green Papaya Salad, Salty and Sweet Chicken, Three-Flavored Fish, Coconut Rice, and hundreds more!. 2nd ed. Cincinnati: F+W Media, 2013. Print.