Cook the sausage until browned well, crumble; set aside.
In the same pan, sauté the mushrooms, onion, garlic, and green chiles.
Combine the sausage with the mushroom mixture; set aside and let cool.
Grease a 9x13-inch glass baking dish and fill the bottom with the prepared bread cubes; top with sausage mixture then the cheese.
Beat together the eggs, milk, sundried tomatoes, basil, sage, dry mustard, salt, pepper, and Tabasco; pour over sausage and cheese in the baking pan.
(This dish can be prepared a day ahead- at this point you'd cover it with plastic wrap and put it in the refrigerator.) In the morning, remove the casserole from the refrigerator and set it out on the counter for 30 minutes.
Preheat oven to 350 degrees F.
Uncover and bake casserole until it's golden and puffy and the center is set, about 50 to 60 minutes.
Cut into squares and serve.
If you want it especially spicy, chop up a jalapeno and sauté it along with the onion and mushrooms; you can also substitute O'Brien potatoes for the bread; you can even substitute vegetarian sausage for the meat!