12 slices firm white bread, cubed
8 ounces Wisconsin cheddar cheese, cubed
4 ounces Wisconsin mozzarella cheese, cubed
8 ounces Polish sausage or cubed cooked ham, or 16 ounces bacon, cooked and crumbled
1 4-ounce can mushroom stems and pieces, drained
2 cups milk
1/4 teaspoon salt
1/4 teaspoon pepper
1/4 teaspoon dry mustard
Butter a 9x13-inch baking dish. Place half the cubed bread in a dish. Cover with the cheese, meat, and mushrooms. Top with remaining cubed bread.
Beat eggs with milk and seasonings. Pour over bread, making sure to coat all of the cubes. Cover and refrigerate overnight, or at least 4 hours.
To finish the strata, preheat the oven to 350°F. Remove strata from refrigerator. Bake for 1 hour or until a knife inserted in the center comes out clean.