1 13.5 oz. can of light/lowfat unsweetened coconut milk
1/2 c. yellow onion, peeled & diced (about 1/2 small or 1/4 large onion)
2 Tbsp. garlic, peeled & roughly chopped (about 4 large cloves)
2 Tbsp. fresh galangal root (a.k.a. "Thai ginger"), peeled & roughly chopped (about a 2" piece)
2-3 fresh, small red Thai chili peppers (i.e., " Bird's-Eye " chilies), stemmed, halved lengthwise, seeded, & de-ribbed1/2 - 1 Tbsp. nam prik pao (chili paste with soy bean oil) (optional)2 tsp. tamarind paste (without seeds)1/2 tsp. salt2 stalks fresh lemongrass, ends trimmed, outer layer removed, cut crosswise into thirds, & pounded with a meat mallet2 small (1 1/2 - 2" long) pieces cilantro root, pounded with a meat mallet (optional)3-4 fresh kaffir lime leaves, stemmed (center veins stripped) & halved (can use frozen or dried as a backup, or skip altogether if unavailable)2 Tbsp. fish sauce
1 1/2 c. fresh, oyster mushrooms or whole straw mushrooms, rinsed, ends trimmed, & thickly sliced
2 c. baby bok choy, chopped crosswise (about 2 small boy choy heads)
18-20 fresh, raw (or if unavailable, pre-cooked) medium-sized shrimp (about 0.6 lbs.), cleaned/washed, peeled, & deveined
6 Tbsp. freshly squeezed lime juice (the juice of 2 large limes)1-2 Tbsp. sesame oil, for garnish (optional)
1 c. vine-ripened tomatoes, cut into wedges & then chopped into thirds (add in raw at end)
4 Tbsp. scallions, sliced crosswise into 1/4" rounds (about 3 large scallions)
1 c. fresh Thai basil leaves, stemmed & halved
1/2 c. fresh cilantro, well-washed & roughly chopped
Directions: Bring chicken broth, water, & coconut milk to a rapid, rolling boil in a large, 8 qt. nonstick stock pot over high heat, about 8 minutes. While liquid is boiling, add onion, garlic, galangal, Thai chili peppers, nam prik pao (if using), tamarind paste, & salt to a food processor & pulse until galangal & garlic have become finely minced & well-combined with the other ingredients. Add this mixture to the soup, once it's come to a boil. Next, add the lemongrass, cilantro root, kaffir lime leaves, & fish sauce. Boil for 5 minutes. Then add mushrooms & baby bok choy, & boil for another 1-2 minutes, or until just tender. (The cooked bok choy should retain some of its firmness & still have a slight crunch to it.) Add the raw shrimp & cook until they turn pink, i.e., only about 1-2 minutes or so under a rolling boil. Turn off stove range & remove pot from heat. Add the lime juice & sesame seed oil (if using) & stir well to combine. Taste soup adjust the seasonings as necessary, to suit your personal preferences. Discard lemongrass & lime leaves before serving. Ladle out soup into bowls.
(If you'll be using pre-cooked shrimp instead, this is the point at which you'll want to add them, i.e., directly to the individual bowls of soup. Since pre-cooked shrimp are already cooked, there's no sense in cooking them further; the object is just to warm them in the soup. Otherwise, they'll become tough & chewy, which doesn't take very long to happen. Shrimp will cook even when they're just sitting in warm soup.)
Garnish each bowl with tomatoes, scallions, Thai basil, cilantro, & additional (sliced) chilies (if desired). Serve hot, accompanied by a plate of lime wedges for those diners who wish to season the soup with additional lime juice.
Yield: Makes 3-4 servings as an entrée, or 6-8 as an appetizer.
Chef's Notes: Most of the above ingredients, especially galangal , lemongrass , & kaffir lime leaves , etc., can typically be found in most Asian markets. Or, if you don't live close to an Asian market, you can buy them online, either separately or as a Thai spice combo pack . My online store stocks many, if not most, of these specialty products. Check the " favorite gourmet groceries " and " favorite herbs & spices " sections.
Substitutions: If you can't get a hold of some galangal, regular ginger root can be used as a substitute, but it really doesn't impart the same flavor to the soup. Also, please be sure to use Thai basil and not regular Italian sweet basil; Thai basil has a peppery taste, & works much better for tom yum. Also, if you don't happen to have any chicken broth on hand, you can easily make chicken stock by boiling pieces of cleaned & washed (raw) chicken in water, leaving the meat on the bone.
Preparation tips: Tom yum typically requires crushed chili peppers & garlic, usually smashed with the back of a heavy knife or in a mortar & pestle. To save time, I used a food processor instead. :) Essentially, the same net effect is achieved: The fragrance & flavor of the spices & herbs have been released.
While it's not customary for Thai cooks &/or their dinner guests to remove the whole, fibrous herbs & spices used to flavor the soup -- i.e., the lemongrass stalks, galangal slices, cilantro root, lime leaves, etc. -- during preparation & serving, I'd recommend that you remove these components for your guests as a courtesy before serving the soup, particularly if they are newbie tom yum eaters. :) Frankly, it's kind of a pain in the neck to fish out the herbs while you're eating the soup, even if you are aware that you shouldn't eat those parts. ;) Plus, your guests will most likely appreciate your extra efforts because you've saved them the trouble of having to go on a minor fishing expedition while they are trying to enjoy their soup. :)
A brief word about fish sauce & its application in Southeast Asian soups: Now some of you who aren't used to the taste of fish sauce might go "ewwww" at the mere thought of it. To be honest, I wasn't exactly a huge fan of it either until rather recently, i.e., after I learned how to use it properly. ;) However, let me assure you this particular soup recipe has a very mild & subtle flavor, and the fish sauce is barely even detectable.
As with most soup seasonings, the trick to using fish sauce properly is knowing exactly how and when to incorporate it into the soup during the cooking process. In fact, the step that makes the biggest difference is the very first one: Just like the process of making phở, the fish sauce should be added to the broth itself as it boils, so it literally gets cooked into the broth, versus being added to the finished bowls of soup as an afterthought, in its uncooked & largely undiluted state, which would just overpower the soup. At least this is what the purists tell me. ;)
As a result, this soup isn't "fishy"-tasting at all. The mere proof of this is that even Erik will eat it, and he absolutely HATES fishy-tasting foods. :)
For the record, I'm not making any of this up. For one, the fish sauce tips were dispensed by traditional, native Southeast Asian chefs who know a thing or two about authenticity. :) And second, anyone who knows Erik fairly well can tell you about his "fish-ues." :) Probably enough to fill an entire book. Don't even get me started. Hahaha. OK, I'm only joking about the latter of the two. Er, sorta. ;) I wasn't going to get into the topic at first, but you know me -- it was just too hard to resist a good pun. ;)
Variations: If you prefer a mild broth, use shallots instead of onions, & be sure to seed & de-rib the chilies.
You can also easily make a vegetarian version of this soup; just leave out the shrimp & the fish sauce, substitute with an organic vegetable broth, & add tofu as your protein source. :)