Preheat oven to 350°. Arrange bread in a single layer in a greased 13x9-in. baking dish. In a large skillet, cook sausage over medium heat 6-8 minutes or until no longer pink, breaking into crumbles; drain.
In a large bowl, whisk eggs, milk, Parmesan, chives and pepper; pour over bread. Add sausage; sprinkle with cheese.
Bake, uncovered, 25-30 minutes or until edges are golden and a knife inserted in the center comes out clean. Let stand 5 minutes before cutting. Sprinkle with additional chives.
To Make Ahead: Prepare casserole as directed. Refrigerate, covered, several hours or overnight. To use, preheat oven to 350°. Remove casserole from refrigerator while oven heats. Bake as directed. Sprinkle with additional chives.