Atún encebollado, or tuna with onions, is a traditional dish from Chiclana de la Frontera. This hearty and flavorful dish features fresh tuna cooked with onions, garlic, tomatoes, and a variety of spices. The tuna is simmered until tender and the flavors meld together to create a rich and satisfying meal. Atún encebollado is often served with crusty bread or rice, and it is a favorite among locals and visitors alike. The combination of the tender tuna and the sweet and savory flavors of the onions make this dish a true culinary delight.