Drizzle some vegetable oil in a casserole dish large enough to hold all the onions.
Cut onions in half crosswise and thinly slice off some of the bottoms of the onion so it can sit in the dish flat.
Place all onions cut side up and drizzle with oil.
In a small bowl mix breadcrumbs with cheese, pepper and paprika and 1-2 tbsp of oil. Sprinkle over tops of onions. Season to taste
Bake in a preheated 350F oven for approx 40-45min until fork tender.