Isn’t it great that one of the dishes that have pretty much put Thai cuisine on the world map is so easy to make? Tom Yum Goong  is a main course soup made by simply cooking whole shrimp gently in simmering infused broth and seasoning it to taste. If you can make a good cup of tea, chances are you’d be good at making Thai hot and sour soup as well.
For the sake of simplicity and practicality, let’s not talk about the version of Tom Yam I had growing up or the version you had growing up for they may be different from one another and/or from the version featured here. Let’s not talk about the various versions of Tom Yam documented in cookbooks from a bygone era by so and so who died in such and such year for the fact that most of us today have never had or continue to make them that way has rendered such discussions useful merely as an intellectual exercise with little relevance.
If I’m right in assuming that the purpose at hand is to replicate the most common version of this iconic Thai soup which you’ve most likely encountered (and fallen in love with) at your local Thai restaurant, then I hope what you find here will serve you well.
With that out of the way, the only things left to mention are as follows:
- This is a very simple recipe, and as you may have noticed from your experience in cooking and baking, the “simpler” the recipe, the more it relies on proper and good-quality ingredients as well as flawless execution. This principle applies here — big time. You need all of the ingredients listed here. All of them need to be fresh. All of them need to be present. None can be substituted (except for the vegetarian version discussed below).
- If you don’t have all of the ingredients listed here, I recommend that you use commercial, ready-made Tom Yam paste that comes in a glass jar or in little cubes. Simply follow the package instructions. This is far better than making Tom Yam with missing ingredients, and nobody should make you feel guilty about using it.
- As opposed to my favorite Tom Yam wherein the broth derives the flavor from bone-in pieces of meat such as oxtails, this shrimp Tom Yam needs some help from other animals. The shrimp won’t impart much flavor to the broth since it’s technically poached in it very quickly, and cooking it longer will only render its flesh tough and rubbery. You need to use a broth, preferably made with chicken or pork bones as most commonly done in Thailand. Beef broth doesn’t work well here; neither does broth made the Western way, i.e. with mirepoix and bouquet garni. Simple, concentrated chicken or pork broth works best.
- If you use commercial broth, be mindful of the sodium content. This recipe is tested with unseasoned broth. If your broth is salty, reduce the amount of fish sauce accordingly.
- Only cilantro is used here to accent the finished soup. I personally like to add some mint leaves in addition to cilantro. Some people add a few fresh Thai basil leaves, but that’s by no means common.
- I don’t like tomatoes in my Tom Yam. However, if the version of Tom Yam you like contains tomato chunks, by all means, add about one medium tomato, cut into 1/2-inch chunks, to the simmering broth the same time you do the mushrooms.
- As mentioned above, shrimp should not be overcooked. In fact, once the broth is done, it’s simply a matter of poaching the shrimp in it. I recommend that you watch the video in which Chef Michael Pardus of the Culinary Institute of America shows his students how to poach shrimp in what he calls “ouch hot” liquid. That video is embedded in my post on how to make Tom Kha Gai. The same principle applies here. You really don’t want to cook the shrimp in boiling liquid.
- A newer, non-traditional-yet-much-loved version of Tom Yam Kung has milk added to it. Evaporated milk seems to be the most common milk of choice. These days, when you order Tom Yam Kung at a Thai restaurant or food stall, you’d be asked whether you’d like your Tom Yam “Nam Sai” (clear broth) or “Nam Khon” (creamy broth). To make Tom Yam Kung Nam Khon (ต้มยำกุ้งน้ำข้น), simply follow the recipe below, replacing 1/2 cup of the broth with evaporated milk or half-and-half. Add the milk to the pot after the shrimp has been cooked. No need to bring the whole thing to a boil; simply heat it through. Some curdling may or may not occur; don’t sweat it.
- For a vegetarian version, start out with vegetable broth and replace the shrimp with tofu or triple the amount of mushrooms this recipe calls for. Use salt instead of fish sauce (I wouldn’t use soy sauce in this dish). Also, if the negligible amount of dried shrimp and shrimp paste in Nam Prik Pao is an issue, you can skip it entirely. The flavor of the end product will be slightly different, but if you’re used to dishes that contain no animal products, you may not notice or be bothered by it.
- 1½ cups unseasoned chicken or pork broth (as concentrated as you can make it)
- 7-8 large shrimp, peeled with the head and tail sections left
- 3-4 fresh kaffir lime leaves, torn into pieces and lightly bruised
- 4-5 slices of lemongrass, approximately ⅛-inch thick
- 4-5 very thin slices of fresh galangal
- ¾ cup canned straw mushrooms (or fresh white mushrooms), drained and halved (see notes below)
- 1 tablespoon of Nam Prik Pao
- 2 tablespoons of fresh lime juice, or to taste
- 2 tablespoons of fish sauce, or to taste (see notes in the post about the sodium level in the broth)
- 4-5 small dried red chilies (I use arbol), broken up
- ¼ cup lightly-packed cilantro leaves
- In a medium saucepan, bring the broth to a very gentle boil over medium heat. Monitor the temperature so that the liquid is not boiling furiously but barely simmering. [We're infusing the broth with fresh herbs in the manner similar to making tea; we're not cooking the life out of them.]
- Add the lemongrass, galangal, and kaffir lime leaves to the broth; continue to monitor the temperature.
- Add the mushrooms.
- Stir in Nam Prik Pao.
- Add the fish sauce, followed by the dried chilies.
- As the broth is gently simmering, lower the shrimp into it while monitoring the temperature somewhat closely (meaning you don’t need to whip out the thermometer but keep an eye on the broth to make sure it doesn’t drop too low that the shrimp won’t cook or surge too high that the shrimp is boiled to death).
- Give the shrimp a couple of stirs. Once the flesh has firmed up and turned opaque, remove the saucepan from heat.
- Season the soup off the heat with the lime juice. Taste. Add more fish sauce or lime juice as necessary.
- Stir in the cilantro leaves and serve the soup piping hot with rice (it is, after all, an entree).
 Officially, Tom Yam Kung. I’ve included the transliteration Tom Yum Goong (which I have not and will never use) here just because is by far the most prevalent transliteration and one that I’m certain you have seen most often. Without including it, confusion may occur as some may not recognize that it’s the same dish we’re talking about here.