The red Tropea onion was introduced to Calabria by the Phoenicians some 4,000 years ago and has always been famous for it's sweet flavour and crunchy texture. In addition to its culinary values, the Tropea onion consortium cite recent research showing that their onions can also help prevent tumours as well as benefit the heart, circulation and digestion. The red colour of the onion indicates that it is rich in anthocyanins which are a powerful antioxidant. While the Tropea onion is iconically Calabrian, all of Calabria, along with the entire Mezzogiorno, were part of the Kingdom of Two Sicilies 200 years ago. This Sicilian dish combines the excellent tuna from Sicily and Calabria with this unique onion using a cooking method brought to Sicily by the Arabs- sweet and sour. The result is an exciting medley of flavours ticking all the boxes of sweet, sour and salty. Enjoy!