As a caveat, one of the 'authentic' elements of most Thai soups is the emphasis on large chunks of aromatics. These woody, membranous, chewy or otherwise inedible bits are simply picked out of the bowl at the table. Generally, this is considered too much work in Western minds, and almost rude of the chef to insist that the diners do all the work of taking out the large (though still edible) chunks. The Thai people are fairly self-sufficient, however, and are happy to share the workload. If you don't like the big chunks in your soup - by all means, strain them out before the soup gets to the table. But be warned, these soups are flavored by the aromatics, and should be served immediately as the soup is heated through. The more time you spend in the kitchen picking out lemongrass and lime leaves, the more the freshness of the flavors diminishes.
The Thai word for shrimp is 'kung'. If you can get shrimp with the heads still attached, great - you can make a quick, very flavorful, broth with these. What we had on hand was some homemade chicken stock and a bag of frozen, peeled, deveined prawns from Trader Joe's. The prawns have the last couple shell segments attached at the tail, so we pulled these off by warming just the frozen tips in water, and boiling these shells in chicken stock for a couple minutes. We've also tried cooking this with a mushroom stock by boiling sliced dried shiitakes, but it wasn't as good. The chicken version of this dish, Tom Yum Gai, is also tasty, but try the prawns if you get the chance; it's more exotic and unusual.
Thai hot and sour soup - Tom Yum Kung (or Tom Yum Gai)
makes 2 servings - easily doubled or tripled
adapted from the Chiang Mai Thai Cookery School cookbook by Sompon and Elizabeth Nabnian
1 1/2 cups water or chicken stock
4-6 prawns with some kind of shell, OR 1 skinless chicken breast
3 cloves garlic, peeled and smashed with the butt of a knife or a pestle
3 small (or 1 large) shallots, sliced
5 thin slices fresh (or 3 dried) galangal, skin removed
1 stalk lemongrass, lower 1/3 only, cut into 1-inch pieces
1/3 can straw mushrooms, halved (unpeeled ones are fun, if you can find them)
8 small cherry tomatoes, halved
2-4 small green Thai chiles, halved lengthwise
1 1/2 Tbl Thai fish sauce
3 magrood (kaffir) lime leaves, torn in half
1 Tbl freshly squeezed lime juice
1/4 cup chopped cilantro
- Have all ingredients sliced, smashed, and measured out before you begin - this soup is quick!
- Bring the stock to a boil in a small saucepan.
- Add the shrimp heads and peels (if using shrimp), and boil for 5 minutes.
- Add the garlic, shallots, galangal and lemongrass (and chicken, if using). Boil for 3 minutes.
- Remove the chicken when just barely pink in the middle, let cool. Shred.
- Add straw mushrooms and tomatoes. Boil another 2 minutes.
- Add chilies, fish sauce, and lime leaves. Cook 2 minutes.
- Add the protein, either prawns or chicken, and gently cook 1-2 minutes, or until just done.
- Remove from heat.
- Add the lime juice and cilantro only AFTER removing from heat. Adjust seasonings as necessary.
- Serve hot, with a small bowl or plate for pulling out lemongrass, galangal, lime leaves and/or chiles.