Bring turkey drippings or stock to a boil over medium high heat in a medium saucepan. Remove from heat and add in mushrooms. Let steep until mushrooms are tender, about 15 minutes. Drain mushrooms, reserving stock. Finely chop mushrooms.

Whisk in flour and cook, stirring frequently, until golden blonde, about 2 minutes.

Gradually add in reserved 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 sherry and heavy cream and continue to cook until warmed through, about 1 minute.

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.