How to Make It
In a small bowl, cover the dried mushrooms with hot water and let soak until softened, about 30 minutes. Drain and rinse off any grit. Discard the stems and thinly slice the mushrooms if necessary.
Heat 1 tablespoon of the vegetable oil in a large saucepan. Add the shallots and cook over high heat, stirring, until lightly browned, about 2 minutes. Add the leek, white and dried mushrooms, ginger and curry powder and cook over moderate heat, stirring, for 3 minutes. Pour in the vegetable stock and coconut milk and bring to a boil.
In a bowl, blend the cornstarch with 1 tablespoon of water until smooth. Stir the paste into the soup and bring to a boil over moderately high heat. Reduce the heat to low and simmer the soup for 30 minutes. Season with salt and pepper.
Heat the remaining 2 tablespoons vegetable oil in a medium skillet. Add the wild mushrooms and sauté over high heat until softened, about 2 minutes. Season the mushrooms with salt and pepper.
Divide the sautéed mushrooms among 4 to 6 soup bowls. Stir the lemongrass and lemon juice into the soup. Ladle the soup into the bowls and garnish with the chopped chives.