Preheat oven to 350 degrees. Grease 9x13 inch pan.
Heat a large skillet over medium heat. Brown the sausage until no pink remains, breaking it up with the back of a wooden spoon. Drain fat.
In the buttered dish, add the hashbrowns, cooked sausage, onions, peppers, and 1 1/2 cups of cheese. Gently mix ingredients together and spread evenly in the dish.
In a large bowl, add the eggs, milk, salt, pepper, and seasonings and whisk together until well combined.
Pour the egg mixture over the hashbrown mixture and sprinkle the remaining cheese on top.
Bake for 55-65 minutes or until cooked through. If not baking immediately, cover with foil and refrigerate. Allow additional time to bake in this case.