Slice a medium onion in 1/4 inch slices, separate into rings and soak in ice water while preparing the following:
Beat 1 egg with 3 tablespoons milk and salt in a bowl. Into 1 paper sack, place 2 cups of flour and into another, 2 cups of bread crumbs.
Drain water from onions and toss a few at a time in the flour sack, making sure all have been coated. Dip each ring into the egg mixture with a fork, turning to completely cover with egg, then toss in crumb sack and coat well. Lay out on waxed paper to dry from 30 minutes to an hour. Fry in deep fat until golden brown. Salt again.