*1. You can use any kind of breakfast sausage for the recipe - spicy is good. I make my own breakfast sausage by thoroughly mixing with my hands 1 lb ground pork, 2 t Italian spice mix, 1 t each salt + pepper, 1/2 t each cayenne + nutmeg. Making it myself guarantees that there aren't any strange fillers or allergens (like gluten) in the sausage.
2. Overnight option: You can prepare this casserole the night before. Fill everything into the casserole dish, sprinkle with cheese, cover the dish with foil and refrigerate overnight. In the morning, continue with the baking instructions in step 5.