Stove and Oven:

1. Heat a pan over medium high heat. Add in the sausage and brown. Drain off excess grease. Turn off the heat.
2. In a bowl whisk together the eggs, milk, mustard, salt and pepper. 
3. Spray a 9×13 inch pan with non-stick cooking spray. Spread the bread cubes in the bottom of the pan. Layer the sausage on top. Pour the egg mixture over everything. Sprinkle with the cheese.
4. Cover with foil and refrigerate overnight. 
5. Bake covered for 30 minutes, then uncover and bake an additional 10 minutes until the center is set and the cheese is lightly golden.
6. Slice and serve. 

Slow Cooker:

1. Heat a pan over medium high heat. Add in the sausage and brown. Drain off excess grease. Turn off the heat.
2. In a bowl whisk together the eggs, milk, mustard, salt and pepper. 
3. Spray a slow cooker with non-stick cooking spray. Spread the bread cubes in the bottom of the slow cooker. Layer the sausage on top. Pour the egg mixture over everything. Sprinkle with the cheese.
4. Cover and cook on high for 2 hours, or until center is set. 
5. Slice and serve.