Whenever we had a party in Delhi, fish tikka always came top of the wish list. Any firm white fish will suffice, and there are plenty of sustainable varieties worth checking out.
Sprinkle the sliced onion with salt and set aside for 20 minutes. Squeeze out any excess water from the onion and pat dry with paper towels. Deep-fry the onion until golden then drain on paper towels.
Transfer the fried onion to a food processor; pour in about 45ml