Preheat oven to 350. Chop all vegetables, trim crust from bed, dice ham. Spray a 8x8 casserole pan with cooking spray, place bread on bottom, press in if needed. On top of bread layer half the ham, cheeses, peppers and mushrooms, then repeat.
In a medium bowl, beat eggs, milk, salt, cayenne pepper and garlic powder together, pour over the ham/veggies and bread. Let it sit for 5-10 minutes. Mix corn flakes and butter and sprinkle over top (optional).
Bake in oven for 30-45 minutes.(You may want to cover with foil if the ham starts getting to brown) The last 5 minutes you will want to remove and add the tomatoes and olives, return to oven and bake another 5 minutes, server with sour cream and salsa if you like.
**** I DID NOT USE THE CORN FLAKES AND BUTTER IN MINE*** lol mainly because I forgot, but it was still really good, I just had to cover with foil and cook about 10 minutes longer