tuna or mullet roe
The salted, dried and pressed, and sometimes smoked roe of tuna and mullet, and sometimes swordfish. It's especially popular in Sicily, Calabria and Sardinia, where it is often known as buttariga (or botterigo).
It can only be made by hand: the roe is carefully massaged to eliminate air pockets, then salted for weeks and dried for up to two months, resulting in a hard slab, which is often coated in beeswax for keeping. It is generally served on thin slices of toast or grated on spaghetti.
Bottarga di Favignana from Sicily, Bottarga di muggine di Cabras (Sardinia) and Bottarga di Orbetello (Tuscany) are in the Ark of Taste.