In a bowl, combine the first 3 ingredients. Stir in the ham, onions, chiles and Worcestershire sauce; set aside.
Cut top fourth off loaf of bread; carefully hollow out top and bottom, leaving a 1/2-in. shell. Cube removed bread; set aside. Spoon ham mixture into the bottom shell, mounding slightly. Replace top; wrap tightly with a double layer of heavy-duty foil. Bake at 350° for 1 to 1-1/2 hours. Stir before serving. Serve with reserved bread cubes, vegetables, crackers or tortilla chips.