First, remove the outer layer of the onions. Then slice them into 1 cm wide slices, and remove central part of the rings
Now grab 3 bowls. Using the first large bowl, place the breadcrumbs inside. Ideally, this should be a shallow bowl. In the second bowl, add the flour. In the third bowl, pour in the milk.
Place the rings a few at a time into the bowl of milk. Then move them to the bowl of flour. Again, place them in the bowl of milk, and finally into the bowl of breadcrumbs. This should create a thick layer of batter. Continue this process until all of the onion rings are battered.
Heat a large frying pan or deep fryer to 350 degrees, and add the oil. Fry a handful of the rings at a time for 2-3 minutes or until they turn a golden brown color.
Place the cooked onion rings on a plate with a paper towel on it. Then sprinkle salt over the onion rings. Once they're all cooked, serve hot and enjoy.