3Cook spaghetti according to package directions and set aside until ready to use.
4Melt the butter in a large saucepan. Stir in the flour, salt and pepper, and whisk to form a roux. Cook until bubbly, then add broth and the cream; keep stirring with whisk until mixture becomes slightly thick. Remove sauce from heat. Stir in the Parmesan and mix until cheese melts.
5Stir in the parsley, sherry, turkey and mushrooms and spaghetti; coating the spaghetti thoroughly.
6Pour spaghetti mixture into the prepared casserole dish.
7Optional: Melt 2 Tablespoons butter and toss with bread crumbs.
Option #2: Instead of buttered crumbs, You can sprinkle some Parmesan cheese over the dish or cheese of your choice.
8Sprinkle over the top of casserole; cover with foil. Bake for 30 minutes or until hot and bubbly. **Remove the foil the last 10 minutes of baking.