Step 1

Preheat oven to 350°. Spray a 13 x 9 casserole dish liberally with cooking spray. Set aside.

Step 2

In a medium mixing bowl, whisk together the milk, eggs, dry mustard, salt, and pepper. Set aside.

Step 3

In a very large mixing bowl, toss together the onion, green and red bell pepper, ham, cheddar cheese, and bread cubes.

Step 4

Pour the egg mixture over the bread mixture and stir to mix. Pour into the prepared baking pan and even out.

Step 5

Bake in preheated oven for 45-50 minutes or until the casserole begins to puff up a bit, the top is golden brown, and the middle feels set. Let cool for 10 minutes before slicing and serving.