Tom Yum Gung (Hot and sour shrimp soup)
6 cups chicken stock
1-2 stalk(s) lemon grass, tough outer leaves removed, cut into 2-inch pieces
10 (5 pairs) fresh or frozen Kaffir lime leaves (bai magroot)
4 tablespoons chili paste in soybean oil
4 tablespoons Thai fish sauce
1/2 cup fresh squeezed lime juice
1/4 cup sugar
1 pound medium shrimp
1/2 pound oyster mushrooms or button mushrooms, wiped clean and sliced
Sprigs of cilantro
Put the stock and lemon grass in a soup pot. Tear up the Kaffir lime leaves and add to the pot. Gradually bring to a low boil over medium-high heat. Keep at a low boil for 1 minute. Stir in the chili paste. Add the fish sauce and lime juice. Add the sugar and stir until it is dissolved and blended. Add the shrimp and mushrooms and simmer just until cooked, about 1 minute.
Ladle the soup into a soup tureen or individual serving bowls. Tear a couple sprigs of cilantro over each serving.
Note: Replace the shrimp with chicken to create tom yum gai.
Serves 4 to 6.