Line unpricked pastry shell with a double thickness of heavy-duty foil. Bake at 450F for 7 minutes. Remove from the oven and remove foil; set aside. Reduce heat to 350F. In a skillet, cook sausage until no longer pink; drain well. Place cottage cheese and egg in a blender; cover and process until smooth. Transfer to a large bowl; stir in potatoes, sour cream, oregano, salt and pepper. Place sausage in pastry shell; top with potato mixture. Drizzle with butter. Bake for 50 to 60 minutes or until set. Sprinkle with cheese; let stand for a few minutes until cheese is melted.