How to Make It
In a large saucepan, heat the olive oil. Add the fennel, carrot, onion, garlic, peppercorns and turmeric and stir over moderate heat until evenly coated with oil. Add 6 cups of water and bring to a boil. Gently simmer until slightly reduced and the vegetables are soft, 15 to 20 minutes. Strain the soup into a large bowl; discard the solids.
Wipe out the saucepan and return the broth to it. Whisk the miso into the broth and cook over low heat, whisking, until hot. Season with salt. Stir in the tofu and simmer until the tofu is warm, about 2 minutes. Serve the soup garnished with chives.