Preheat oven to 325F. In a 9” x 13” x 2” baking dish, put enough of the bread pieces into the bottom of the pan to make a thin layer. Make a layer of ham, broccoli and cheese. Whisk together the milk, eggs, salt, and dry mustard. Pour over top. Toss remaining bread with butter/ sprinkle over the top of the casserole. Bake for 45 minutes. Let cool for about 20 minutes. Cut into squares.