These onion rings hide a pocket of cheddar between two nested rings, and a splash of tonic water in the batter is what keeps the panko shell from turning heavy: the fizz lightens the mix so the coating crisps properly in the air fryer. Choose pairs of rings that sit snugly inside each other and pack the cheese in firmly, or it will leak as it melts. Fifteen minutes at 200°C (400°F) is usually enough; look for deep golden panko all over before you pull them out. Cold sparkling water works in place of tonic if that is what you have.
Instructions
- 1
Slice the onions into ~0.5 cm rounds and separate the rings. Pick pairs of similar-sized rings with a small gap between them.
- 2
Stuff the gap between each paired ring with cheddar cheese.
- 3
Batter: combine 1 cup flour, 2 tbsp cornstarch, 1 tsp baking powder, 1 tbsp salt. Add a splash of tonic water and mix to a smooth, pourable batter.
- 4
Dip each stuffed ring in the batter to coat fully, then roll in panko breadcrumbs.
- 5
Air fry at 200 °C (400°F) for 15 minutes until golden and crunchy.
15:00 - 6
Serve hot — crisp shell, gooey cheese, tender onion in every bite.
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Notes from our kitchen
We spend most of the prep time matchmaking rings. Two rings of nearly the same size, one just inside the other, leave a channel the cheddar can sit in; mismatched pairs leave gaps, and the cheese runs out onto the basket the moment it melts. Packing it in tightly and covering every spot with batter and panko is what seals it.
The batter should pour slowly off a spoon. If it is too thick the panko clumps; too thin and it slides off the rings. We pull them when the crumbs are an even deep gold and we can hear the shell crackle when tapped. Rushing the coating and leaving bare patches is the usual reason a ring leaks.
Variations
- Bake them instead. No air fryer? Bake the coated rings on a wire rack at 220°C (425°F) for 18–20 minutes, turning once, until the panko is deep golden.
- Swap the cheese. Mozzarella melts into longer strings and gives a milder pull; smoked gouda works well too. Whatever you choose, cut it from a block so it packs firmly into the gap.
- Make ahead. Coat the stuffed rings up to a day ahead and keep them covered in the fridge; the panko stays put and the batter sets, which helps seal the cheese.
Frequently Asked Questions
Why use tonic water in the batter?
The carbonation makes the batter light and crisp — the bubbles aerate it so the coating fries up airy rather than dense. Cold sparkling water works too.
How do I stop the cheese leaking out?
Pick matching ring pairs with a small gap, pack the cheese in snugly, and coat fully in batter and panko so there are no bare spots for it to escape.
Can I bake these instead?
Yes — bake at 220°C on a rack until golden, about 18–20 minutes. The air fryer is faster and gives the crispest shell.