Isola Signature sauces are among the finest.   The unique taste comes from Carmelina Brand San Marzano plum tomatoes grown in only one place on earth; the rich volcanic soil in the shadow of Mt. Vesuvius.   Porcini from the Italian Swiss Alps, Southern Italian artichokes, eggplant and lillyputs, sundried tomatoes, zucchini flowers and distinct seafood accentuate five varieties.