Fill the reserved mushroom caps (usually 20 to 25) with the reserved stuffing and broil for 5 minutes, coordinate the time to have them done when the turkey is ready to carve.
To de-fat the liquid from the roasting pan pour it, plus the other liquids into a skimmer jug, allow to stand until you see the fat floating on top. Carefully pour the liquid out the jug until you reach the fat, discard the fat.