Peel the onions and cut in half horizontally. Place the onion halves in plenty of salted water for about 10 minutes.
Remove from the water, dry a little and place in a baking dish with the surface facing up. Season with salt and pepper. Spread the breadcrumbs and chopped parsley on the surface and drizzle with olive oil.
Place in the oven preheated to 180 ° C for approx. 60 - 75 minutes.