ok it’s not perfect yet, but i think is about as close as i’m going to get… my most recent batch came out pretty well, so here’s the recipe i adapted it from (with my notes in italics):
Tom Yam Goong (spicy prawn soup)
3/4 lb prawns in the shell
1 tsp oil
3 c. chicken or fish stock (i actually used 3 c. of homemade shrimp stock with some of the same flavors – lemongrass, kaffir lime leaves, chiles, etc, and then used 2 c. chicken broth instead of the water, below)
2 c. water
3 stalks lemongrass, cut in 1/2 in. slices
2 small red chili peppers, sliced (i ended up using 5!)
1 clove garlic, minced
1 1-inch piece galanga, sliced
1 cup sliced mushrooms (i used button mushrooms the first batch, and straw the second, either works fine)
5 kaffir lime leaves
1/2 onion, thinly sliced
1 stalk celery, thinly sliced
1 red bell pepper, thinly sliced
2 limes, juiced (i ended up using both lime and lemon juice)
1 tbsp. fish sauce
3 green onions, sliced
1/4 c. cilantro leaves and stems, sliced
(i omitted the red pepper and celery but added sliced bamboo shoots… of course, most of this can be adjusted “to taste”)
Remove the shells from the prawns, set aside. Slice the prawns in half lengthwise and refrigerate.
In a large soup pot, heat the oil and sautee the prawn shells until pink. Add the stock, water, lemongrass, lime leaves, chili peppers, garlic, and galanga. Bring to a boil. Lower the head, cover and simmer for 60 minutes. (using this method, you can always make a double batch of the stock and save some in the freezer for another batch of soup.)
Strain the stock mixture then return it to the pot. (I had to strain a few times to get all the the sediment out, using cheesecloth.) Bring to a boil and add the mushrooms, onion, celery, and red pepper. Reduce the heat and simmer for 2 minutes.
Add the prawns and simmer for another 2 minutes. Add the lime juice, fish sauce, green onion, and cilantro just before serving.