Remove the ends and papery peel from a sweet onion. Turn the onion on its side, and cut it into ¼ to ½ inch thick slices. Once you've sliced the entire onion, use your fingers to pull the rings apart. Set aside.

Now it's time to make the breading station. In a bowl, combine ½ cup all purpose flour, ¼ teaspoon baking powder, pinch of salt, and ½ cup of water. Stir to combine and remove most of the flour lumps. Then add more 2 or 3 Tablespoons of water, a Tablespoon at a time, until it's the consistency of waffle batter (a little thicker than pancake batter).

On a dinner plate, combine ½ cup of panko breadcrumbs with ½ teaspoon (or several shakes) of seasoning salt. Panko works best when it's very dry. So I recommend starting with this small amount of seasoned breadcrumbs, and then replenishing as needed while breading the onion. If the panko gets too damp, don't be afraid to throw it away and start over with a clean plate.

Now it's time to bread the onion rings. One at a time, dip an onion ring into the wet batter. Drip off any excess batter. Then dredge it in the seasoned panko. Put the coated onion ring on a separate clean plate. Continue with the remaining onion rings. As you run out of panko breadcrumbs, continue replenishing with another ½ cup of panko + ½ teaspoon of seasoning salt until all of the rings are breaded.

TO AIR FRY: Put the onion rings into the air fryer basket, being careful not to overfill. Roughly a single layer works best.(They won't brown as nicely if the basket is too full. You may need to cook in batches. Remember that subsequent batches will cook faster since it will already be hot.) Spray the onion rings with oil spray for browner rings. (If you prefer to cook oil free, you can omit the spray.) Air fry at 400 degrees for 6 to 8 minutes. (The exact time will vary, depending on your specific air fryer & if the basket is very full.) If the onion rings aren't as brown as you'd like, carefully turn them over & spray again with more oil. Then continue cooking.Once they have browned to your liking, move the onion rings to a bowl, and finish with a pinch of salt. Serve with ketchup or your favorite dipping sauce.

TO PAN FRY: Bring a large skillet to a medium high heat with about an inch of avocado oil (or your preferred high heat oil). Drop a breadcrumb into the oil. If bubbles immediately form around it, the oil is ready for frying.Put several onion rings into the oil. (Be careful not to overfill, or they won't brown as nicely. You'll need to work in batches.) Fry the onion rings for a couple minutes on one side. Once they're brown on one side, carefully flip with a spatula and cook for a couple minutes more, until perfectly brown all over. Move the browned onion rings to a plate lined with paper towels or a clean kitchen towel for oil drainage. Top with a pinch of salt. Continue frying the remaining onion rings until all of them are fried. Serve with ketchup or your preferred dipping sauce.