Place bread cubes in greased 9x13 rectangular baking dish. Layer sausage mixture over bread. Top with cheese and green onion.
Combine eggs, milk, sour cream and pepper. Pour evenly over layers in casserole. Cover and refrigerate 2-24 hours.
Preheat oven to 325°. Bake, uncovered, 50-55 minutes or until knife inserted in center comes out clean. Let stand 10 minutes.