Cook 6 ounces spaghetti and drain. Mix with 2 eggs and 1/4 cup Parmesan cheese. Layer in pie pan as crust. Spread 1/4 sour cream and sauteed onions over top. Mix filling, 1 pound Italian sausage (precooked) and 8 ounces of spaghetti sauce and 1 cup water. Cook and layer over sour cream. Bake at 350 degrees for 25 minutes. Take string cheese and place over top as lattice. Cook for another 5 minutes.