Add fennel to your tomato soup for the an ultra-cozy dish.
In pot, cook sliced fennel, the onion, and carrot in oil over medium-high heat, stirring often, until beginning to soften, about 7 minutes. Add tomatoes and stock; simmer until vegetables are tender, about 15 minutes. Puree soup; season. Garnish soup with fennel fronds and drizzle with olive oil.