When I told my sister that we were going to feature some of our dad’s Thai home-cooking on the blog, she enthusiastically said, “Oh Dad makes the BEST tom yum soup!” I think she’s right. I’m hard-pressed to find a better one at any Thai restaurant – with generous pieces of fish, shrimp, and scallops (my favorite). The key to his soup is making sure to get the right balance of sweet, sour, salty, and spicy – you really do need to taste the soup and adjust the seasonings so that they equally satisfy all four senses. Limes vary in size, acidity and sweetness – so use your tastebuds as your guide and the listed amounts in the recipe as suggestions.
Notes: Thai soups are fragrant and spicy from all the fresh aromatic herbs and chilies. There will be large chunks of galangal, lemongrass, and lime leaves in the final soup that are not meant to be eaten, but are there to flavor the soup. You can fish them out before you serve, or do as the Thais do, and just eat around them. Lemongrass, lime leaves (a.k.a. makrut or kaffir lime leaves), and galangal can be found in the produce section of most Asian supermarkets and some well-stocked grocery stores. If you cannot find lemongrass or kaffir lime leaves, you can substitute strips of lime or lemon zest. You can also substitute ginger for the galangal. It will not have same flavor, but the soup will still taste good. Thai fish sauce or nam pla, can also be found in Asian supermarkets or in the Asian section of a well-stocked grocery store.
My dad uses scallops, salmon, and shrimp for the seafood in this soup. You can use any combination of seafood (mussels and other firm-fleshed fish work well) or substitute cut-up chicken.