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