Bring a large pot of water to a boil for the egg noodles. When it boils, salt the water and cook the noodles to al dente. Drain well and return to the pot.
Preheat a large, deep nonstick skillet over medium-high heat. Add the bacon. Cook for 2 to 3 minutes, until the fat is rendered and the bacon begins to brown at the edges. Add the turkey and brown it, crumbling with a wooden spoon. (If using leftover turkey, add the turkey after you cook the mushrooms and onions instead). Move the meat over to one side of the pan and add the mushrooms and onions to the opposite side. Cook the mushrooms and onions for 3 to 5 minutes, then stir the meat and veggies together. Season the mixture liberally with salt and pepper, and sprinkle in the poultry seasoning. Cook for another 5 minutes. Add the wine and deglaze the pan, using a wooden spoon to scrape up the pan drippings and browned bits. Stir in the broth and bring to a boil, then stir in the cream and reduce the heat to low. Add the nutmeg and stir. Taste and adjust seasonings if necessary.
Preheat the broiler to high. Combine the noodles with the turkey and sauce. Spray a casserole dish with nonstick spray, then transfer the turkey noodle mixture to the dish. Top the casserole with the Gruyere then bread crumbs. Place the casserole 8 to 10 inches from the broiler and brown 2 to 3 minutes until cheese is melted and the crumbs are brown. Remove from oven and garnish the casserole with parsley.
Notes
If you're trying to use up leftover turkey, you can certainly use chopped turkey in place of ground turkey. Just heat the turkey in the skillet with the rest of the ingredients. Maybe use about 2 1/2 cups.