Preheat oven to 375°.
Brown sausage in 12-inch nonstick skillet over medium heat. Add onion and cook, stirring occasionally, 5 minutes or until tender.
Stir remaining ingredients except bread into same skillet; stir in bread.
Evenly spread mixture into 13 x 9-inch baking dish, then press lightly. Bake 30 minutes or until golden and heated through.