1. Preheat Oven to 325. 2. In large skillet cook sausage over medium-high heat until no longer pink. 3. In large mixing bowl combine eggs, chives, milk, mustard, and salt. Stir well. 4. Distribute half of bread evenly in a buttered 9x13x2 inch baking dish. 5. Sprinkle with half of pepper, add half of cheese, add half the sausage. 6. Repeat layering process. 7. Pour egg mixture evenly over casserole. 8. Bake uncovered for 60 minutes or until eggs are set. (Tent with foil if top begins to brown too quickly). Maybe be prepared up to 12 hours ahead and refrigerated.