Add the minced ginger, chopped green chilli, cumin, ground coriander, dried coriander leaf, chilli flakes, ground fenugreek, salt, garlic salt, gram flour, cornflour (cornstarch), and the bicarbonate of soda.
1 tbsp minced ginger, 1 green chilli, 1 tsp ground cumin, 1 tsp ground coriander, 1 tbsp dried coriander leaf, 1 tsp chilli flakes, 1 tsp ground fenugreek, 3/4 tsp salt, ½ tsp garlic salt, 130 g (1 ½ cups + 2 tbsp) gram flour, 1 tbsp cornflour (cornstarch in USA), ½ tsp bicarbonate of soda
Mix together to coat the onion.
Add in the water, a tablespoon at a time, until you have a thick batter that coats the onion. It needs to be a sticky, thick coating that holds together.
4-6 tbsp water
Spray (or brush with a little oil) your air fryer basket. This will help stop the onion bhajis from sticking.
Take a rounded tablespoon of the onion bhaji and squeeze the mixture in your hand compact it. Flatten it down a little (this will give you more surface area for crispness and will ensure more even cooking) then place it into the air fryer basket.
Repeat with the remaining mixture (you should get about 10-12 bhajis altogether). You may have to work in 2-3 batches depending on the size of your air fryer. Each bhaji needs a little space around it, so don't overcrowd the basket.
Spray the bhajis with oil (or brush a little oil on each).
Air fry at 200C/400F for 10 minutes, then turn the bhajis, spray with more oil and air fry for a further 5-7 minutes until dark golden brown all over.
Once all of the onion bhajis are cooked, place in a serving bowl and sprinkle with fresh coriander. Serve with sweet chilli sauce or your favourite sauce.
1 tbsp finely chopped fresh coriander (cilantro)
Notes
Cooking in batches?
I usually make these in two batches. If you need to do this, or if you're making multiple batches, you can keep cooked batches warm on an uncovered baking tray, in a warm oven (approx. 130C/250F (fan)), whilst cooking the remaining bhajis.
Can I make them ahead?
The onion bhajis will be at their crispiest when freshly cooked, but you can make them ahead if you prefer.Make the bhajis, then cool, cover and refrigerate for up to two days. Reheat in the air fryer at 200C/400F for 3-4 minutes, until hot throughout. Alternatively reheat on a tray (uncovered) in the oven at 200C/400F for 5-7 minutes.
Can I freeze onion bhajis?
Yes, make the bhajis, then cool, cover and freeze for up to a month. I find it's best to freeze them on a tray, so they're not touching, then after a couple of hours (when they're fully frozen), transfer to a sealed container or freezer bag.Defrost overnight in the refrigerator, then reheat in the air fryer at 200C/400F for 3-4 minutes, until hot throughout. Alternatively reheat on a tray (uncovered) in the oven at 200C/400F for 5-7 minutes.
Ingredient swaps
Use red onions for a milder onion flavour and hint of colour.
Add grated carrot, parsnip or courgette (zucchini) for extra veg
Change up the spices if you fancy a change - add more chilli flakes to make them hotter, swap out the cumin and coriander for your favourite curry powder, add more ginger for a bit of zing!
Nutritional information is approximate, per onion bhaji.