Cooking the Ribs. Lower the temperature of the oven to approximately 400 degrees Fahrenheit and place the pan with the beef ribs in it. Ensure that the lid is properly placed. Cook at this temperature for about 45 minutes.Then slow cook the beef ribs in the oven for three hours by lowering the temperature further to about 200 degrees Fahrenheit. Slow cooking the meat enables the maximum amount of fat to melt away.nsure that the lid is properly placed. Cook at this temperature for about 45 minutes. Then slow cook the beef ribs in the oven for three hours by lowering the temperature further to about 200 degrees Fahrenheit.