In a skillet, cook bacon until crisp; add ham and onion. Cook and stir until onion is tender; drain. In a greased 13x9x2 inch baking dish, layer half the bread cubes, potatoes and cheese. Top with all of the bacon mixture. Repeat layers of bread, potatoes and cheese. In a bowl, beat the eggs; add milk, Worcestershire sauce, mustard, salt and pepper. Pour over all. Cover and chill overnight. Remove from refrigerate 30 minutes before baking. Bake, uncovered at 160ºC or 65-70 minutes or until a knife inserted near the