Breakfast Egg Casserole

So I made this recipe for the last Speaking Seminar and I think it went over pretty well. We use the original mild style breakfast sausage, NOT sage. I especially love this recipe because to me, this is Christmas morning, along with cinnamon and orange rolls, more on those to come. This is simple and easy to make but it does require a day in advance to prepare.

12 slices of bread
1/2 lb cooked, crumbled sausage
6 eggs, beaten
2 C. milk
1 tsp. dry mustard
1/2 tsp salt
1/2 lb. grated cheddar cheese
Dash of pepper

Beat eggs slightly and then add milk. Mix well. Mix salt and dry mustard together and then add to egg mixture along with pepper, mix well. Butter 9x13" pan. Layer 6 slices of bread on bottom of pan. Top with sausage, then cheddar cheese. Layer 6 more slices of bread and butter tops. Pour egg mixture over top and cover. Refrigerate overnight. Bake at 350 for 35-45 minutes or until egg is set.