The town of Cabras, a few kilometres west of Oristano, is the bottarga capital of Sardinia. Several producers sell directly from their premises, and the local market (held on Saturdays in the main piazza) is a good place to buy it alongside fresh fish from the lagoon and local pecorino cheese.
Bottarga di muggine — the grey mullet roe — comes in two forms: whole compressed sacs to slice yourself, or pre-grated for pasta. The sacs keep for months and travel well. The best way to eat it is thin-sliced over warm bread with good olive oil, or grated over spaghetti with garlic, parsley, and a little lemon.