Preheat the oven to 350 degrees
Spray cooking spray in a 13 x 9 glass baking pan
In a mixing bowl put the eggs, salt, pepper, and milk and wisk till combined
Fry up the sausage loose in a skillet and drain
Place your bread side by side and cover the bottom of the glass pan
Cover bread with 1/3 of cheese
Put sausage on top of cheese
Put mushrooms on top of the sausage
Layer another 1/3 of cheese
Pour the eggs over the entire thing making sure they will soak down in the bread
Top with the rest of the cheese
Cover with aluminum foil and put in the refrigerator for at least 8 hours.
On Christmas morning, you simply turn the oven on to 350 degrees, remove the casserole from the refrigerator and slide it into the oven, leaving the aluminum foil on. Set the timer for 30 minutes. When the timer goes off, remove the foil and set the timer for 15 minutes. When the timer goes off, just pull it out of the oven and cut squares for everyone!
Have a great Christmas,