Melt ½ cup butter in a large saucepan or small stockpot. Add the flour and cook, stirring constantly, for 3 minutes to cook and make a roux.
Add the milk, stock, wine, salt and pepper. Cook over medium heat, stirring often, until thickened – about 8 to 10 minutes.
In a separate saucepan, melt the remaining 3 tablespoons butter. Add the sliced mushrooms, green peppers and garlic. Sauté until cooked through. Season with the ½ teaspoon salt.
Place the cooked pasta, chicken or turkey and mushroom mixture in a large mixing bowl. Add half of the sauce and ½ cup of the Parmesan cheese. Mix gently to combine.
Spray a large casserole pan with nonstick food spray. Place the mixture evenly in the pan. Pour remaining sauce over the casserole and sprinkle top with the remaining Parmesan cheese.
Bake in a 375 degree preheated oven for approximately 40 minutes or until heated through and lightly browned.
Recipe courtesy of Chef Terri Milligan