Conservas Ortiz Ventresca de Bonito del Norte, White Tuna Fillets in Olive Oil, imported from Spain. This tuna comes from the ventresca (belly) of the fish, the most tender part of the white tuna. Considered by many the finest cut of tuna, you'll notice a distinct lack of fish-smell when you open a tin and a delicate flavor making any added ingredients unnecessary. Conservas Ortiz prepare their white tuna in Ondarroa, northern Spain, using only unbroken fillets, hand-packed in olive oil. Conservas Ortiz practices sustainable fishing using fresh, live bait and trolling techniques.