Wiktionary
bottarga
n. A Mediterranean dish of cured fish roe
Wikipedia
Bottarga
Bottarga is the Italian name for a delicacy of salted, cured fish roe, typically of the grey mullet frequently found near coastlines throughout the world, that often is featured in Mediterranean cuisine and consumed in many other regions of the world. The food bears many different names and is prepared in several different ways.
The product is similar to the softer cured mullet roe, karasumi from Japan and East Asia. Sometimes the delicacy is prepared from tuna.