Lay the bread cubes on the bottom of an 8x11 casserole dish. Layer ham, asparagus, then red pepper over top. (Note: you want to use very thin asparagus in order to avoid having to steam it first. If you cannot find thin, steam first for 2-3 minutes.)
In a mixing bowl, whisk together milk, eggs, salt, and pepper.
Pour egg mixture over top of the bread layers.
Lay the six slices of cheese over top of the casserole.
Cover tightly with foil and refrigerate over night, or for at least two hours.
In the morning, preheat oven to 375 degrees. While oven is preheating, set casserole dish on the counter to warm up.
Bake for 40-50 minutes, or until a knife inserted in the center comes out clean. Garnish with green onions.