White Tuna Belly In. Olive Oil Premium, Espinaler.The Bonito del Norte tuna is caught in the Cantabrian Sea to the north of Spain. This cut of tuna, also known as ventresca, comes from the underside (belly) of the fish that has a more tender and moist meat. It is manually tinned in whole chunks to maintain the natural texture and avoid any deterioration of the fat between the layers of fish. Tin is presented in a ready to serve box. Ingredients: Bonito del Norte tuna, olive oil and salt. WARNING