Gradually add in turkey drippings or stock in a steady stream, whisking constantly. Bring to a boil, reduce to a simmer, and cook until reduced to 3 cups, 10 to 15 minutes.
Stir in heavy cream, sage, thyme, and rosemary. Continue to cook until warmed through, about 2 minutes. Season with salt and pepper to taste. Serve immediately or store in an airtight container in refrigerator for up to a week, reheating over medium-low heat before serving.