Su filindeu, or "threads of God," is the rarest pasta in the world. For a century, it was made by a single family in the Sardinian city of Nuoro for religious celebrations. Today, there are fewer than 10 people there who know the secret to making the pasta as thin as a strand of hair. Secrecy nearly led to the dish’s disappearance, but now, the pasta is finding new customers abroad. We went to Italy to see how the process of making su filindeu is still standing.