Preheat the oven to 375 degrees F.
Cook the spaghetti in a large pot of salted water, according to package instructions. Drain well.
Meanwhile, melt 6 tablespoons of butter in a small saucepan over low heat. Add the flour and cook for 2 minutes, constantly stirring with a wooden spoon.
Raise the heat to be medium and whisk in the milk. Cook, constantly whisking, until the mixture comes to a boil and thickens. Remove from the heat and whisk in 1/2 cup of Parmesan, the nutmeg, 1 teaspoon salt, and 1/4 teaspoon pepper.
Melt 6 tablespoons of butter in a large skillet over medium heat.
Add the Gruyere on top and cook, stirring, until melted. Stir in the turkey, wine, condensed soup, and parsley.
Add the cooked spaghetti and toss well.
Transfer the mixture to a 9 by 13-inch baking dish and sprinkle with the remaining 1/4 cup Parmesan.
Bake for 30 to 35 minutes, until the sauce, is bubbly and the pasta is browned around the edges.
Enjoy!