Filindeu is tied to a religious ritual celebrated in the region of Nuoro. Oddly, this celebration is tied to a murder in the year 800 AD. Accused of murder and being hunted down for his crime, a young man claimed innocence and took refuge in a cave about 15 miles from Nuoro. He was discovered, brought to trial and miraculously (to him) declared innocent. He had prayed to Saint Francis during his time of refuge in the cave and thus built a shrine in the cave in honor of his patron saint. Every May 1st and October 4th, there are processions to the cave and shrine followed by a celebratory feast of filindeu.
This process is repeated until a single layer of "threads" cover the entire fundu. the basket is then rotated by about 60 ° with another layers of pasta "threads" laid down. This is repeated a third time creating three criss-crossed layers of "threads". The tray is placed in the sun to dry causing the three layers to stick together while creating a stiff fabric of pasta looking very much like a course textured cheesecloth.
If you're ever in Sardinia, look for packages of filindeau shards. Some have realized that this is a real Sardinian treasure and are trying to expand the availability of this pasta.