Sausage Souffle

Put 6 slices cubed white bread in 9x13 casserole.  Brown 1 pound mild sausage in skillet; drain.  In mixing bowl, beat 5 or 6 eggs; add 1 cup grated sharp cheddar, 1 tsp dry mustard, ½ tsp salt, 2 cups milk and 1 can cream of mushroom or celery soup.  Add browned sausage to mixture and pour over cubed bread in dish.  Refrigerate overnight.  Put in cold oven and bake at 350º for 1 hour (or until set).  Serves 6-8.