In a food processor, chop celery, onion, and fennel. Heat oil in a large pot over medium heat, add vegetables, and cook until softened, stirring often, about 7 minutes. Add wine, 1 cup water, tomatoes, chile flakes, salt, and pepper. Cook, covered, 8 to 10 minutes to let flavors develop. Add crabs and cook, covered, stirring often, until warm and fragrant, about 5 minutes. Transfer to a large serving bowl. Whirl herbs together in food processor to chop, then sprinkle over crab and serve with warmed bread.
Note: Nutritional analysis is per serving.