Mom's Holiday Breakfast Casserole

Courtesy of my Mom

1 pkg. Pork Sausage; cooked, crumbled & drained
10 eggs, lightly beaten
3 cups milk
2 tsp. dry mustard
8 oz. (2 cups) shredded sharp cheddar cheese
6 c. cubed bread
1/2 tsp black pepper
1 tsp salt
1/2 c mushrooms, sliced (optional)
1 medium tomato, chopped (optional)
1/2 c. green onions, sliced (optional)

Preheat oven to 325* F. In a large mixing bowl, combine eggs, milk, mustard and salt. Distribute half the bread evenly in a buttered 9" x 13" x 2" baking dish. Sprinkle with half the pepper, half the cheese, sausage and optional ingredients. Pour egg mixture evenly over casserole. Bake uncovered for 55-60 minutes, or until eggs are set. Tent with foil if top begins to brown too quickly. Makes 6 servings. Can be made the night before and refrigerated before baking.