Literally, the words "tom yam" are derived from two Thai words: "tom" and "yam". "Tom" refers to boiling process, while "yam" refers to a Thai spicy and sour salad. Indeed, tom yum is characterised by its distinct hot and sour flavours, with fragrant spices and herbs generously used in the broth. The basic broth is made of stock and fresh ingredients such as lemongrass, kaffir lime leaves, galangal, lime juice, fish sauce, and crushed chili peppers.