Cube the bread and place it in a lightly greased 8-by-11-by-2 inch casserole.
Fry the sausage until it is almost browned completely and drain on some paper towels. Mix the half-and-half, dry mustard, salt, pepper, hot sauce and eggs together. Layer the sausage over the bread and top with a generous layer of potatoes. If you are using mushrooms, layer them in before the potatoes. Sprinkle the cheeses on the top. Pour the beaten egg mixture over the casserole. Cover and refrigerate 1 hour to overnight.
Preheat the oven to 350 degrees F.
Bake the casserole until it is set and does not jiggle in the middle, 30 minutes.
A viewer or guest of the show, who may not be a professional cook, provided this recipe. It has not been tested for home use.