While the turkey rests, it’s time to prepare the gravy:
Strain the pan juices through a sieve into a large measuring cup and discard the solids. Skim off the fat from the top. (Optional- save the vegetables, fruits, and giblets in a large pot to make homemade turkey broth).
Add enough chicken broth to the pan juices to make 4 cups.
Melt the remaining 5 tablespoons of butter in a saucepan over medium-high heat. Whisk in the flour and cook for 1 minute.
Gradually whisk in the broth mixture. Simmer, whisking often, until the gravy thickens, about 10 minutes.
Taste and season with salt, pepper, and the optional poultry seasoning as needed.