Points to remember
- Use a fork to steady your onion and slice the onion into rings about 1cm wide. Remove the skin and separate the rings.
- Heat the oil to 180C in a heavy-based pan – it should be no more than 1/3 full.
- Meanwhile mix the batter ingredients - here we use flour, seasoning and sparkling water. Whisk together to form a thick batter.
- Coat a small batch of onion rings and carefully lower them, one at a time into the hot oil.
- Deep-fry until crisp and golden, about 2 - 3 minutes. Drain on kitchen paper. Repeat until you have cooked all the onion rings.
It's worth investing in a cooking thermometer to measure the temperature of the oil. You can, however, drop a cube of bread into the oil to test the temperature. It should brown in 45 seconds – 1 min.