In a small bowl soak roll in water. Heat 2 T vegetable oil in a frypan; cook chopped onion until lightly browned. Transfer onion to a bowl. Squeeze roll as dry as possible and mix roll with onion. Add ground beef; blend well. Season with salt and pepper. Shape meat inot 4 patties; cook about 5 minutes on each side or to desired doneness. Remove and keep warm. Add sliced onions to pan drippings; cook until lightly browned. Arrange beefsteaks on a platter and top with onion rings.