Strain the turkey drippings into a fat separator or measuring cup and let stand until the fat rises to the top. Separate the fat from the pan juices, then add enough low-sodium turkey broth to the juices to measure 4 cups.

In a 3-quart saucepan over medium heat, combine the turkey fat with enough unsalted butter to make 1/2 cup total and melt.

Whisk in the flour and cook for 2 to 3 minutes, whisking constantly, until the roux is smooth and lightly golden.

Gradually whisk in the 4 cups of pan juices and broth until smooth, then bring to a simmer and cook for 5 to 8 minutes, whisking often, until thick enough to coat the back of a spoon.

Stir in the salt and pepper, taste, and add more salt if needed.