Salted mullet roe ( called "bottarga" in Italian) is a food speciality that comes from Sardinia island.
It's also called Mediterranean caviar because it's just fish eggs ( mullet ones are very esteemed because of their gentle taste but you can find bottarga made with tuna eggs and others) salted, pressed and matured.
Once bottarga was the lunch of fishermen when they were all day long on their boats: eggs and fish entrails were a property of "tonnarotti" ( fishermen who fish tuna), nowadays it' s a common pasta season: it must be grated the same way you do with Parmesan and it's the best way to serve and taste it.
For 4 serves you need:
1 garlic clove
extra-virgin olive oil in plenty
a piece of bottarga (about 2 1/2 oz.)
1 pound spaghetti
fresh parsley if you like, washed and chopped
Cook spaghetti in boiling water with salt (less than usual because bottarga is already salad).
Meanwhile grate bottarga, take a large bowl (large enough to serve pasta), pell the garlic clove and rub it on the whole inside of the bowl, then leave it on the bottom.
Add oil in the bowl, a lot of oil, grease the sides of the bowl too then sprinkle sides and bottom with a part of grated bottarga.
Drain spaghetti "al dente" with a big fork and put them in the bowl (don't use the classic colander because it could dry pasta too much).
Add the rest of bottarga, some more oil if needed, parsley.
Mix well and serve.
P.S. : you can find bottarga already grated or fresh, vacuum packed: prefer the second one, the aroma is better preserved than the first one!