These are best served the moment they come out of the fryer. From Southern Living.
Cut onions into 1/2-inch slices, and separate into rings.
Set aside.
Whisk together flour and next 4 ingredients until smooth.
Pour oil to a depth of 2 inches into a Dutch oven; heat to 375°.
Dip onion rings in batter, coating well.
Fry, a few rings at a time, until golden.
Drain on paper towels.
Serve immediately.