This recipe was sent via email from All-recipes with a video showing onion rings that not only fry up crispy but STAY that way. The reason he reported is in the secret ingredient, instant mashed potatoes in the batter and panko crumbs.
As an update: Made these and while the taste is good and they certainly stayed crispy, for some reason I had trouble getting the coating to stick when cooking. I think maybe I didn't have the oil hot enough when I started, or maybe I needed a 2nd breading?? Not really sure, but if anyone has an idea please let me know.