Belly of Bonito in Olive Oil. The belly or belly of bonito is the juiciest and softest part, being made fresh and artisanally during the Bonito del Cantabrico campaign or season during the summer months, a true delicacy in canned form. Conservas Costera, a family cannery from Gijón, carries out a production process that preserves its flavor and juiciness for 6 years from the date of preferred consumption. Gourmet preserves perfect for your table.