Whisk together the aquafaba and chickpea flour until it is a pasty batter.
Combine the breadcrumbs and seasonings well.
Cut the onion into 1/4 inch thick slices, and then separate the rings.
Dip each ring into the batter and shake off excess coating.
Toss the ring in the breadcrumb mixture until well coated.
Gently place on a parchment or silicon lined baking sheet, or the air fryer pan.
Bake at 375 degrees for 20-30 minutes (watch closely in the final 10 minutes to ensure they don't burn). Adjust temperature and time for air fryer accordingly (all are a little different).
Notes
You might have some extra batter or panko coating depending on the size of your onion. I erred on the side of caution in the amounts to accommodate a slightly larger onion. If you have some left, use some of the remaining onion and make another serving!No aquafaba? No problem! Just use water instead, and add a bit extra chickpea flour - the chickpea flour will thicken the mixture and help the crumbs coat your rings.