1. Crumble sausage into a medium skillet; cook until evenly brown; drain.
2. In a medium bowl, mix together mustard powder, salt, eggs and milk.
3. Add the sausage, bread, and cheese, and stir to evenly coat.
4. Pour into a greased 9x13 baking dish.
5. Cover and chill for 8 hours or overnight.
6. Preheat oven to 350 degrees F.
7. Cover and bake 45-60 minutes.
8. Uncover, reduce heat to 325 degrees, bake for an additional 30 minutes.