Tom yum goong requires a very short albeit unique shopping list:
shrimp
limes
straw mushrooms
cilantro
fish sauce
galangal
kaffir lime leaves
lemon grass
nam prik pao (roasted chili paste)
Serrano chilis (optional)
You’ll probably have to go to a Thai market to get the galangal, kaffir lime leaves, and nam prik pao, but you should be able to find everything else at a Chinese market, or even a well-stocked super market. Ginger can be substituted for the galangal, but it’s not quite the same. Omission of any one of the ingredients can change the flavor of the soup tremendously, although not detrimentally.
Start with a pot of 4-5 cups of water over high heat. Add several slices of the galangal, and several kaffir lime leaves, as well as a couple of stalks of lemon grass lightly crushed and cut up into 1-2 inch pieces. Add about 4 tablespoons of fish sauce and 2 tablespoons of the nam prik pao. Bring to a boil. Add the straw mushrooms and the juice of 4-6 limes to the pot and bring back to a boil. Add the shrimp and cook just until they are opaque. Finish by adding some coarsely chopped cilantro. To increase the heat, sliced Serrano chilis can be added. You should end up with about 2-3 servings.
From start to finish, the soup can be ready in about twenty minutes. If you don’t like shrimp, just leave them out and you’ll have tom yum kai. Or you can add coconut milk and have tom yum nam khon. It’s an excellent recipe to have in your repertoire as it’s impressive in its composition despite its relatively uncomplicated construction. Just remember not to eat the galangal, kaffir lime leaves, or lemon grass. While they add to the flavor, they are largely inedible.
