Preheat the oven to 415 degrees.Place your bread into a food processor and pulse until breadcrumbs. Pour crumbs into a bowl and add in the parmesan cheese. Set aside.In a large baking tray, place your onion rings. Drizzle with olive oil and massage into the onions.Season the onions with salt, pepper and then pour over the breadcrumbs, carefully coating all of the onions with the mixture.Bake in the oven for 15-20 minutes. Plate when finished and enjoy!