Spread croutons on bottom of ... over croutons. Whisk eggs and milk. Stir in soup, spinach, mushrooms, cheeses and mustard. Pour egg mixture ... 10 to 12 servings.
Crumble and brown sausage and drain. Beat eggs with milk and salt. Layer bread cubes, sausage, and cheese in 9 x 13 x 2 inch casserole. Pour egg mixture on ... Serves 6 to 8.