This deliciously easy Sausage and Egg Breakfast Casserole recipe is made with eggs, sausage, and cheese and is pretty great starter casserole. But don’t be afraid to use your favorite seasonings and herbs, chopped vegetables, meats and your choice of cheeses.
In a large mixing bowl, beat the eggs, milk, ground mustard, salt and pepper for 1 minute or until completely combined.
Stir in the cooked sausage, bread cubes (you can also use croutons for a different flavor) and cheese. Pour everything into a 9 x 13 baking dish.
Cover and refrigerate overnight or at least 10 hours for best results, however if you want to make it sooner, allow it to sit at least an hour and mix everything up gently with a spatula before putting in the oven.
If you decided to refrigerate overnight for the best results, allow the casserole to sit at room temp for 30 minutes before baking. Bake, uncovered for 30-40 minutes at 400 degrees. If the top starts browning too much (everyone's oven varies) cover with tinfoil and continue baking. Be careful the dish will be hot.
Remove from oven and insert a knife into the center. If knife comes out clean, it's done. Allow to sit for about 10 minutes uncovered. Cut into slices and serve immediately.