In a large 11 x 14 inch lasagna/roasting pan sprayed with cooking spray, spread 1 large bag of thawed (if frozen) shredded hash browns (I use 2 bags of the refrigerated brand, and southern style).
Generously season with salt, pepper, Lawrys and garlic salt (optional). Spread 2 cups of shredded cheddar cheese to cover potatoes.
Sprinkle cooked sausage, bacon or ham crumbles if desired over cheese.
Saute 1 1/2 cups chopped onion, 1 large green pepper, 1 large yellow or red pepper in butter until tender (I use a bag of the stop light peppers, 1 ea of green, yellow and red). Sprinkle over last layer.
Saute 8 ounces sliced mushrooms in butter until tender. Sprinkle over last layer.
2 medium tomatoes, sliced (I use 4-6 Roma tomatoes sliced) should be layered next (optional).
12 ounces of Canadian bacon can be added for the next layer (optional)
Spread 2 cups of shredded mozzarella or combination cheeses like Colby and Monterey, etc. over last layer.
In large bowl, whisk 12 eggs with about 2 cups of milk. I add about 2 tablespoons of hot sauce to the egg mixture, mixing well. Pour over the casserole. Using a spatula, gently press all over to soak the ingredients with the egg mixture. Let stand for 15 minutes. Bake casserole for 35-45 minutes, until egg mixture is set. I add 8 slices of Provolone cheese to the top as it I take it out of the oven for added cheese flavor. Cool slightly before slicing.