Panko is a type of breadcrumbs made with bread that is made to be lighter and crispier than the more traditional breadcrumbs, it is a very good breading to use to get the best crispy cheese sticks. However, other gluten free breadings work very well. Alternatively, you can make your own breading with dry gluten free bread that you grind into a fine breading with a mixer. If you don't have any dry gluten free bread, don't panic, just dry it in the oven for a few minutes and then grind it in a blender.