Heat the olive oil in a Dutch oven over medium heat. Add the garlic and fennel; cook until just soft and fragrant, about 4 minutes. Add the carrots and season with salt and pepper; continue cooking, stirring occasionally, until the carrots are just soft, about 4 minutes. Add the vermouth and boil to reduce slightly. Add the tomatoes and tarragon, then cover the pot and simmer until the vegetables are tender, about 15 minutes. Stir in 1/2 cup water and the mussels. Raise the heat to high, cover and cook until the mussels open, 3 to 5 minutes. (Check halfway through and transfer any open mussels to a serving bowl.) Transfer all the mussels to a serving bowl, discarding any that do not open. Season the sauce with pepper and, if needed, salt, and pour over the mussels. Serve with the bread.
Photograph By Antonis Achilleos
Courtesy of Food Network Magazine