Mediterranean Cabbage Soup

Heat oil in a large heavy pot over medium-high heat. Add carrots, fennel and onion; cook, stirring occasionally, until starting to soften, about 5 minutes. Add garlic, coriander and salt; cook, stirring constantly, until fragrant, about 1 minute. Add broth and tomatoes; bring to a boil. Add cabbage; reduce heat to medium. Cook, stirring occasionally, until the cabbage is tender, 20 to 25 minutes.

Stir in beans, sugar and oregano; cook until the beans are heated through, about 3 minutes. Sprinkle with lemon zest and reserved fennel fronds, if desired; serve immediately.