Tom som

Tom som (ต้มส้ม, ) is a sour soup of Thai origin which usually contains seafood or chicken.

Etymology
The word tom means "boil", and som means "sour".

History
The soup is typically made in northern Thailand. According to Chumpol Jangprai, the Thai word "som" has traditionally been used to describe anything that is sour.

Ingredients
According to Thai chef Bo Songvisava, the broth includes a sour ingredient such as sour tamarind (som makaam), bilimbi (taling pling), nipa palm vinegar (nam som jaak), or roselle flowers (dok krajieb sod) in a chili paste including krill paste (kapi), coriander root, fish sauce, and shallot. Usually a seafood such as shrimp or fish or other meat such as chicken is added near the end of preparation time.

Production method
The ingredients are simmered to make a broth, then often strained through a sieve or cheesecloth. Just before serving, small pieces of seafood or chicken are added and simmered just until cooked.

Serving
Tom som soups are eaten as a meal, as part of a meal, or as aahaan kap klaem (drinking food).