- 2 tablespoons butter
- 2 cups sliced white button mushrooms
- 1/2 cup sliced green onions, white and green parts
- 6 slices country-style bread, cubed
- 2 cups shredded Cheddar cheese, divided
- 2 cups milk
- 8 large eggs
- 1 teaspoon red or green hot pepper sauce
- 1/4 teaspoon salt (optional)
- Softened butter, for the baking dish
- Butter a 9-inch square glass or ceramic baking dish; set aside
- Melt the butter in a medium skillet over medium heat. Add the mushrooms and cook for about 5 minutes or until softened and browned at the edges. Stir in the green onions; set aside.
- Place half the bread cubes in the prepared baking dish. Scatter half the mushroom mixture and half the cheese over the bread cubes. Layer the remaining bread cubes and mushroom mixture in the dish; set aside.
- Beat the milk, eggs, hot pepper sauce, and salt, if using, in a large bowl until well blended. Pour over the bread cubes in the baking dish and top with the remaining cheese. Cover the dish with aluminum foil and refrigerate for 8 to 10 hours.
- Preheat the oven to 350 degrees F. (Allow dish to sit at room temperature while oven is heating.) Bake the casserole, covered, for 45 minutes. Remove the foil and bake for another 15 minutes or until the top is puffed and the cheese is browned at the edges. Let stand for 5 minutes before serving; cut into squares.