Cook pasta shells according to package directions. Meanwhile, in a small skillet, cook pork over medium heat until no longer pink; drain and set aside. In a saucepan, bring water to a boil. Add spinach; boil for 1-2 minutes or until wilted. Drain and squeeze dry; chop the spinach.
In a bowl, combine the pork, spinach, egg, 1 tablespoon Parmesan cheese, cream, garlic, salt, nutmeg and pepper. Drain shells; stuff with the pork mixture. Spread 1/4 cup spaghetti sauce in an ungreased 1-qt. baking dish.
Place stuffed shells in dish; drizzle with remaining spaghetti sauce. Sprinkle with remaining Parmesan cheese. Cover and bake at 400° for 15 minutes. Uncover; bake 10-15 minutes longer or until heated through.