Egg and Sausage Casserole

Name: Egg and Sausage Casserole
Ingredients: 1 1/2 pounds sweet Italian sausage, crumbled; 8 scallions, chopped; 4 ounces mushrooms, sliced; 9 slices sandwich bread, torn into chunks; 8 ounces sharp cheddar, grated and divided; 10 large eggs; 3 cups whole milk; 1 teaspoon Worcestershire sauce; 1 teaspoon dry mustard; 1 teaspoon kosher salt; 1/2 teaspoon fresh ground black pepper; 1/4 teaspoon paprika