Hot and Sour Prawn Soup
Dtom Yum Gkoong or Tom Yum Goong*
A Recipe of Kasma Loha-unchit
Recipe Copyright © 1995 Kasma Loha-unchit.
(Click images to see larger version.)
- 1 lb. medium- to large-size prawns with shells on
- 4-5 large stalks lemon grass (dta-krai)
- 10 thin slices fresh galanga (kha), or 4 dried pieces
- 1 1/2 quarts water
- 4-6 kaffir lime leaves (bai ma-gkrood)
- A tablespoon-size chunk wet tamarind (from a compressed seedless block)
- Good-quality fish sauce (nahm bplah), to the desired saltiness
- 15-20 fresh Thai chillies (prik kee noo), stem removed and smashed to bruise with the side of a cleaver
- 1 small onion, quartered and sliced crosswise 1/4-inch thick
- 3-4 Tbs. roasted chilli paste (nahm prik pow) (Roasted Chilli Paste recipe)
- 6 to 8 oz. fresh oyster mushrooms – keep small caps whole, cut large caps through the stem in half
- 4 green onions, cut into thin rounds (use white and most of green parts)
- 2 small firm tomatoes, cut into small wedges (optional)
- Juice of 2-3 limes, to desired sourness
- 1/2 cup cilantro leaves or short cilantro sprigs
Shell, devein and butterfly the prawns, saving the shells to make soup stock. Place in a bowl and cover with salt water (dilution rate: a teaspoon sea salt to 1/2 cup water). Slosh the prawns around in the water to clean and refresh them. Let sit 5 to 10 minutes, then drain and rinse in several changes of water to remove all the salt. Drain well and set aside. Prawns should not be icy cold when you are ready to cook them. Leave them out at room temperature at least 1/2 hour before cooking.
Trim off and discard the woody bottom tip of the lemon grass stalks and remove the loose outer layers. Cut the trimmed stalks from the thicker end at a very sharp slanted angle about 1/2- to 1-inch apart, exposing the moist inner core, to yield pieces about 1 1/2-inches long. Use most of the stalk, up to about a couple of inches from where the grass blades start. Slice the galanga and set aside.
Wash the prawn shells and drain. Place in a soup pot, add water and bring to a boil over medium-high heat. While waiting for the water to come to a boil, smash each piece of lemon grass with the side of a cleaver to bruise and release the aromatic oils and add immediately to the pot. Tear the kaffir lime leaves at several places to the midrib to release their aroma and add to the pot along with the sliced galanga. When the water comes to a rolling boil, reduce heat and simmer covered for about 20 to 30 minutes to draw out the herb flavors.
Meanwhile, place the chunk of tamarind in a bowl and add 1/4 cup water. Using your fingers, mush the soft, moist flesh of the fruit to mix it into the water. Keep working with your fingers until there is no more soft parts to be dissolved. If the mixture becomes too thick and it is difficult to separate the non-dissolvable pulp from the juice, add a little more water and work the tamarind a little more. Gather up the remaining pulp with your fingers, squeeze dry and discard. The result should be a thick, brown fluid the consistency of fruit concentrate.
When the broth is ready, add fish sauce to salt the broth to the desired saltiness and a little more (i.e., make it a bit saltier than to taste since the lime juice will dilute the saltiness later). Stir in the bruised whole Thai chillies. Cover and simmer a few minutes to infuse the broth with the heat of the chillies to the hotness level you desire. Then strain out all the herbs, chillies and prawn shells with a wire-mesh scooper.
Add the sliced onion and simmer a few minutes, until the onion starts to soften. Stir in the roasted chilli paste (näm prik pow) and tamarind juice. Bring the broth to a rolling boil over high heat.
Add the oyster mushrooms, cover and return to a boil. Add the prawns, stir and after 20 to 30 seconds, turn off heat. Add the green onions, tomato wedges (if using,) and lime juice to the desired sourness. Stir in the cilantro and serve immediately. Do not let the prawns overcook.
Serves 8 to 10 with rice and other dishes in a shared family-style meal.
Kasma's Notes and Pointers for Hot & Sour Soup:
Dtom yum is a light soup with practically no oil, and it contains the four main flavors – hot, sour, sweet and salty – accentuated with fresh aromatic herbs. (See Creating Harmonies with Primary Flavors.) It is the most popular soup in Thailand and can be found in the tiniest mom-and-pop village rice shop to the fanciest restaurant in Bangkok. No menu is without it, even in Thai restaurants overseas, and if there is no menu, as is the case in Thailand's rural areas, just speaking the magic words"dtom yum" is enough to procure a steaming bowl of the fragrant and stimulating soup.
Dtom yum can be made with just about any type of seafood or meat, or vegetables for vegetarians. You can have a dtom yum gkai (gkai = chicken), dtom yum bplah (fish), dtom yum talay (mixed seafood), dtom yum hed (mushrooms), and so on.There are numerous ways of blending flavors, as you will notice from eatingDtom yum in various restaurants here or in Thailand. Flavors vary from place to place, from chef to chef and from pot to pot. But basically,dtom yum is hot and sour – hot from some kind of chilli pepper and sour primarily from lime juice – and has lemon grass as the leading herb flavor.
Most dtom yum in Thailand is made, of course, with Thai people's favorite chillies, prik kee noo, known now in the western world as "Thai chillies." In this recipe, the chillies are kept whole, so you and your guests can spot them easily and not bite into one unless you choose to. Simmering the chillies in the broth will flavor the soup with its special spicy flavor. If you can find red ones, they make the soup prettier and are even easier to spot, but if you want to insure a zero chance of a fiery accident, you may wish to simmer the chillies in the soup stock a few minutes and then strain them out entirely. Remember, the longer you cook chillies, the more their heat will cook out into the surrounding broth.
Alternatively, for a stronger roasted flavor, you may wish to use dried red chilli peppers. Roast them on a dry pan directly over a burner until the pods are dark red, turning frequently so they do not burn. Cut each roasted pepper into two or three segments and add to the soup. Keep in mind, however, that the nahm prik pow in the recipe already provides some roasted flavor.
You might enjoy learning how to Cook Thai food from Kasma in a Thai cooking class.
Kasma teaches this recipe in the Evening Series Beginning Class #2.
*Because the Thai language has its own script, there are different ways of transliterating Thai into English. The more phonetic version is Dtom Yum Gkoong; the more usual spelling is Tom Yum Goong. See A Note on Thai Pronunciation and Spelling.