Put croutons in a buttered 13" x 9" pan. Top with grated cheese. Place sausage on top of cheese. Beat eggs and mix in soup, milk, dry mustard and mushrooms.
Pour over sausage and refrigerate overnight. Bake at 300 degrees F. for 1-1/4 to 1-1/2 hours.
Suggested Handi-Foil Products:
20394 – Cook-n-Carry 13 x 9 Utility Pan w/Lid