Stir 1-3/4 cups stock, lemon juice, basil, thyme, and 1/8 teaspoon black pepper in a medium bowl. Heat remaining stock, remaining black pepper, celery, onion, and mushrooms in a 4-quart saucepan over medium-high heat to a boil. Reduce heat to low. Cover and cook for 5 minutes or until vegetables are tender. Remove saucepan from heat. Add stuffing to saucepan and mix lightly. Remove package of giblets and neck from turkey cavity. Rinse turkey with cold water and pat dry with paper towel. Spoon stuffing lightly into neck and body cavities. Fold any loose skin over stuffing. Tie ends of drumsticks together. Place turkey, breast side up, on a rack in shallow roasting pan. Spray turkey with cooking spray. Brush with stock mixture. Insert meat thermometer into thickest part of meat, not touching bone. Roast at 325 degrees for 3-1/2 to 4 hours or until thermometer reads 180 degrees F. (Stuffing in the turkey should reach 165 degrees.)
Baste occasionally with stock mixture. Begin checking for doneness after 3 hours of roasting time. Let turkey stand for 10 minutes before slicing.