Carabaccia is a traditional Tuscan onion soup documented since at least the 1500s, making it one of the older recorded dishes in central Italian cuisine. The origin of the name is debated — theories point to an old term for a type of onion, an ancient word for a serving vessel, or an Arabic word for squash — but no single derivation is confirmed.
The core ingredients are onions, olive oil, bread, and broth. Thinly sliced onions are slowly caramelized in olive oil over low heat, stale bread is added to soak up the flavor, and a savory beef or chicken stock broth is poured over the mixture.
Carabaccia is considered an ancestor of French onion soup — it is said to have traveled to France with Catherine de' Medici and evolved there. Modern variations add Parmesan cheese, a splash of red wine, or balsamic vinegar to balance the sweetness of the onions.