Preheat oven to 375 degrees. Grease an 8x8 or 9x9 pan. Unfold crescent rolls into strips and press together on bottom and sides. Whisk eggs, milk, mustard and pepper together. Sprinkle the sausage and potatoes, then the cheese on top of crescent rolls. Pour egg mixture over all. Sprinkle with parmesan cheese. Bake 40-45 minutes until no liquid in center.