Preheat the oven to
200º C. Line a baking tray with butter paper.
Cut onions into 1 cm
thick slices, separate the rings and keep them on a plate.
Take egg whites in a
mixing bowl, add cayenne pepper powder, salt and black pepper powder and beat well. Add the onion rings and mix well. Add milk and mix well. Set aside to marinate for 10 minutes.
Add cornflour, refined
flour and garlic powder and mix well.
Spread panko
breadcrumbs in a large plate. Roll each onion ring in the breadcrumbs and keep on another large plate.
Heat sufficient oil in a
deep pan.
Arrange some onion
rings on the prepared baking tray and spray some oil on them, keep the tray in the preheated oven and bake till the rings become golden.
Slide in the crumbed
onion rings into the hot oil and deep-fry on medium heat till golden. Drain on absorbent paper.
Arrange the oven
baked onion rings on one plate and the deep-fried onion rings on another plate. Serve immediately.