Heat one or two tablespoons of oil in a large nonstick skillet. Press ground beef into doughnut shaped patties (the hole in the center will allow it to cook more evenly and will fill in as they shrink during cooking). Dip each patty into flour on both sides and place in hot skillet over medium heat. Cook for a few minutes on each side, until browned. Scoot patties to one side and add onions to skillet. Stir and cook for a few minutes until lightly browned. Pour in 1 cup beef broth and cover. Allow to cook until meat is no longer pink in the center, about ten minutes.