Preheat oven to 350°F (175°C) and grease a 9x13 inch baking dish.
Brown the pork sausage in a skillet over medium-high heat until fully cooked; drain rendered fat.
In a medium bowl, whisk eggs, milk, dry mustard, salt, and pepper until homogeneous.
Distribute bread cubes, cooked sausage, and shredded cheese evenly in the baking dish.
Pour the egg mixture over the dry ingredients, ensuring all bread is moistened.
Bake for 45 minutes or until the internal temperature reaches 160°F (71°C) and the top is golden brown.
Remove from oven and let rest for 10 minutes to set before serving.