Melt butter over medium high heat in medium saucepan. Whisk in flour and cook, stirring frequently, until golden blonde, about 2 minutes. Gradually whisk in turkey drippings or stock in a steady stream. Bring to a boil, reduce to a simmer, and cook until reduced to 3 cups, 10 to 15 minutes. Remove from heat and season with salt and pepper to taste. Serve immediately or store in airtight container in refrigerator for up to a week, reheating over medium-low heat before serving.