Tonno con cipolle in agrodolce (tuna with sweet and sour onions) - Sicilia
Prep time
Cook time
Total time
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!
Recipe type: Main Course (Secondo)
Cuisine: Sicilia
Serves: 4
  • 300 grams red onions, preferably Tropea, skin and ends removed and finely sliced
  • 15 grams / 1 tablespoon sugar
  • 60 mls / 4 tablespoons vinegar
  • 15 mls / 1 tablespoon olive oil
  • 600 grams fresh tuna, sliced into 4 steaks which are 1.5 to 2 cm thick
  • Flour, to dust (optional)
  • Sea salt
  1. Place the onions in a saucepan with 100 mls of water.
  2. Head the pan over medium heat, cooking for 25 minutes. Add more hot water as needed so it stays moist.
  3. Add the sugar and vinegar with a pinch of salt to the onions. Cook for 5 more minutes.
  4. Dust the tuna steaks on both sides with flour and sprinkle with a bit of salt.
  5. Heat a large frying pan over medium high heat. When hot, add the olive oil and swirl around the pan to evenly coat it. Add the tuna steaks ensuring they are not overcrowded. Sear the tuna on each side for 1 to 2 minutes (or more depending how cooked you like your tuna).
  6. Serve topped with the sweet and sour onions. For a nice presentation or to serve as a starter, slice each tuna steak and fan out the slices before topping with the onions.
Recipe by Living a Life in Colour at