Preheat oven to 375 degrees.
Chop the ham into cubes. I used around 2 cups. You can add more or less depending on your desires.
Crumble the bread into small pieces.
Mix the bread, cheese, and ham together. Spread evenly in a greased 13×9 casserole dish.
Crack and beat the eggs.
Add the milk, salt, and ground mustard to the eggs and mix well. Pour over the ham, cheese, and bread in the casserole dish.
Bake in the oven at 375 degrees for about 40 minutes.