Preheat oven to 250F. and line a large baking sheet with paper towels. With
a mandoline or other manual slicer, slice onion paper thin and separate
into rings. In a deep kettle or deep fryer heat 2 inches oil to 375F. While
oil is heating, in a large bowl stir together flour and chipotle rub.
Dredge onions in flour mixture; shake off excess flour & deep fry until
onions are crispy. Serve Hot.