Saute half the onion in a skillet; cool.
Soak white bread in milk for 2-3 minutes.
Mix together beef, pork, raw and cooked onions and soaked bread. Add salt, pepper and egg; stir up well.
Shape meat into flat patties. Roll them in bread crumbs.
Fry patties in oil on both sides, approximately 2 minutes on each side, until they become brown.
Preheat oven on 375°F.
Bake in the oven for 10 minutes.
Turn off the heat but keep in oven another 5-7 minutes before taking them out.