Remove the ends and peel the onion.

Thinly slice it using a mandolin. They should be almost translucent.

Next, in a deep bowl or cake dish, whisk together the buttermilk, egg, salt, and pepper until combined. Set it aside.

In a separate deep bowl or cake dish, mix the flour with the southwest seasonings. Set it aside.

Fill a medium-sized pot of oil filled to the halfway mark to 350°.

Take a handful of the sliced onions and place them in the buttermilk-egg mixture pan and mix until coated.

Shake off any excess buttermilk and transfer them to the pan with seasoned flour and thoroughly mix until the onions are breaded on all sides.

Remove any excess flour and place in the hot oil and fry them for 2 to 4 minutes.

Using a slotted spoon move the onions around so they don’t clump together and cook evenly.

Place on a sheet tray with a rack or paper towels and drain any excess oil. Cook in batches.

Serve hot or keep warm.