If you are using a potato chip coating, start by processing your potato chips into crumbs. Put 3 big handfuls of potato chips (roughly 3 ounces) into a food processor. Grind them on a low setting until they become crumb-sized. You may need to stop occasionally to stir for even grinding. That should make about 1/2 cup of potato chip crumbs. If you don't have enough crumbs, add more potato chips to the food processor and grind them, as needed. (If you're using panko bread crumbs, you can skip this step, of course.)
Next, set up your work area with 3 plates. Put corn starch on one plate, vegan mayonnaise on the second, and potato chip crumbs or panko bread crumbs on the third.
Add dried basil, dried oregano, granulated onion, salt, and pepper to the crumbs. Combine thoroughly with your fingers or a spoon.
Blot the slices of green tomato on a clean towel, so that they are as dry as possible. Then dip each slice into the cornstarch, making sure it's totally covered. Tap each slice against the plate to knock off any excess cornstarch. Then dip each slice in the vegan mayonnaise. Again, make sure it gets fully coated, but wipe off any excess. You don't want there to be big blobs of mayonnaise. It should feel smooth and painted on. Finally, dredge each slice in the crumb mixture, making sure each one is totally covered.
Put the slices in an even layer across the bottom of the air fryer basket.
If you're using a potato crumb mixture, there's no need to spritz oil on the green tomatoes. They have plenty of oil in them already. Air fry the slices at 400 degrees for 7 minutes. Don't flip or shake them. Because the potato chip crumbs are on the heavy side, they will fall off if you jostle them too much in the air fryer.
If you're using a panko bread crumb mixture, give the green tomatoes a spritz of oil. Air fry at 400 degrees for 5 to 7 minutes. Stop to check on them. Once they are nicely browned, they are ready to flip. Flip them, give another spritz of oil, and air fry for 2 more minutes. Add another pinch of salt to the green tomatoes just before serving.