Cook sausage until well browned, drain fat. Break it up as you cook it so it is like ground sausage. Press crescent roll dough into a 9 x 12 cookie sheet or an ungreased 12 inch pizza pan with points toward the center. Press over bottom and up sides to form a crust; seal perforations (important) Spoon sausage over the crust. Sprinkle with potatoes and top with cheddar cheese. (You can make it to this point the night ahead of time, cover with plastic and refrigerate) In a bowl beat together eggs, milk, salt and pepper. Pour over crust in the middle – it will seep out to the edges on its own. If you pour it near the edges it may overflow. Sprinkle with Parmesan cheese over all. Bake at 375 oven for 25-30 minutes.