1. Heat the oil in a large saucepan. Add the sliced carrots and ginger and cook over moderately high heat, stirring, until the carrots are crisp-tender and lightly browned, 6 to 7 minutes. Add the onion and cook until softened but not browned, about 2 minutes.
2. Add the chicken stock, water, coconut milk and curry paste to the saucepan and bring to a boil. Simmer over moderate heat until the carrots are tender, about 25 minutes. Strain the cooking liquid into another saucepan, reserving the solids; discard the ginger. Transfer the carrots to a blender and puree with 1 cup of the cooking liquid until very smooth. Return the puree to the cooking liquid, add the carrot matchsticks and cook until tender, about 3 minutes. Season with salt and pepper. Ladle the soup into bowls, sprinkle with the scallion, cilantro and basil and serve.
Make Ahead: The soup can be refrigerated for up to 1 day.
Wine Recommendation: To contrast with the coconut milk, ginger and red curry paste in this soup, try an aromatic, fruity California white, such as the 1997 Trefethen Dry Riesling or the 1997 Pine Ridge Chenin Blanc.
Notes: Red curry paste is available at Asian groceries and by mail order from The CMC Company (800-CMC-2780).