What is the main vegetable in caponata?

The main vegetable in caponata is eggplant.

Caponata is a Sicilian dish built around chopped, fried eggplant, combined with vegetables and a distinctive agrodolce sauce. Agrodolce means “sweet and sour,” a flavor created with ingredients such as vinegar and sugar. Tomato, celery, olives and capers are also common components.

The dish is usually served as a salad, relish or antipasto, either warm or at room temperature. Its contrasting textures and flavors—soft eggplant, tangy vinegar, briny olives and gentle sweetness—are central to the classic Sicilian style.

Peppers and tomatoes can appear prominently in particular recipes, which can make them seem like the main ingredient. They are supporting vegetables, however, while eggplant supplies caponata’s characteristic body. Recipes vary across Sicily, and some elaborate historical versions include seafood, but the standard vegetable caponata remains eggplant-based.