Cut the large sweet onion into ¼ inch slices and separate into rings.

Place onions and milk into a bowl and refrigerate for 15 minutes to marinate.

In a large deep pan, heat oil to 365-370 degrees.

In a small bowl mix together vinegar, flour, salt, garlic powder, and pepper. Dip the onion slices into the flour mixture until they are all coated.

Pour the milk and the egg into the flour mixture and stir until blended using a fork. Dip the floured rings into the batter to coat, then place on a wire rack to drain.

Deep fry a few at a time for 2 to 3 minutes, or until golden brown (turning midway).

Place on paper towels to drain. Add salt to taste.