Onions contain a variety of natural chemicals that have are capable of fighting infections and healing the human body.
Probably that is the reason why Onion is used in most dishes.
This snack is not a very healthy option due to frying, but once in a while we indulge in home made deep fried snacks rather than outside food.
Its better to discard the oil once used, so use as little oil as possible even if it means frying 2-3 rings at a time.