Preheat oven to 350°. Cook pasta according to package directions. Meanwhile, sauté mushrooms 4 minutes in 2 Tbsp. melted butter in a large skillet over medium-high heat. Add onions and garlic; sauté 3 minutes. Stir in wine, and cook 4 minutes or until liquid almost evaporates. Add half of spinach, and cook, stirring constantly, until wilted; repeat with remaining spinach. Stir together shredded turkey, mushroom mixture, cooked pasta, and 1 cup stuffing mix in a large bowl.
Heat remaining 3 Tbsp. butter in a large saucepan over medium heat until foamy. Whisk in flour, and cook, whisking occasionally, 3 minutes. Whisk in milk and chicken broth, stirring until combined and smooth. Increase heat to medium-high, and cook, whisking often, 10 minutes or until mixture begins to bubble. (Do not boil.) Whisk in salt, pepper, and 1 package garlic-and-herb cheese; simmer, whisking often, 4 minutes or until thickened. Add milk mixture to pasta mixture; stir until well blended. Spoon mixture into a well-greased (with butter) 9- x 13-inch baking dish. Dot with remaining package garlic-and-herb cheese; sprinkle with remaining 1 cup stuffing mix.
Bake at 350° for 20 to 30 minutes or until browned and bubbly. Cool 5 to 10 minutes before serving.
Note: We tested with Boursin Garlic & Fine Herb Gournay Cheese and Stove Top Stuffing Mix for Turkey.