Make-Ahead Turkey Gravy

INGREDIENTS

• 2 teaspoons vegetable oil
• 3 turkey necks
• 1 onion, chopped
• 1 stalk celery, chopped
• 1 carrot, chopped
• 1/3 cup Marsala wine
• 2 quarts cold water
• 1/4 ounce dried porcini mushrooms
• 2 cloves garlic, peeled
• 1 bay leaf
•  
• 1/4 cup butter
• 3 tablespoons flour
• 2 tablespoons heavy cream
• salt and freshly ground black pepper to taste