How to Roast Turkey a Day Ahead 1. Prepare and roast the turkey as you usually do, with or without stuffing. (Line the turkey cavity with cheesecloth before adding stuffing to make removal of stuffing from cooked bird much easier.) 2. While turkey cooks, cook potatoes with garlic cloves, then mash with sour cream, cream cheese, and pepper - recipe follows. ( Be sure to save potato cooking water to make the gravy.) 3. When turkey is fully cooked, remove from oven; let stand at least 20 minutes before slicing. 4. Transfer whole turkey to cutting board for slicing. Remove stuffing and place in microwave- safe or ovenproof dish,. Cover and refrigerate. Pour pan juices into large measuring cup or bowl; remove and discard fat. Pour some of the pan juices onto the bottom of a 13 x 9-inch baking dish - enough to cover bottom. Use 2 dishes if turkey is large. Set a cake cooling rack in baking dish or dishes. Cover with a sheet of aluminum foil. Poke holes all over the foil. 5. Transfer remaining pan juices back to roasting pan and make gravy using potato-cooking water. Transfer gravy to storage container; cover and refrigerate. 6. Slice turkey, separating white and dark meat if desired. Layer slices in prepared baking dish - do not place more than 1 ½ inches of sliced turkey in each dish. Cover tightly with foil and refrigerate. Be sure to save and refrigerate or freeze carcass to make stock. 7. One hour before dinner time, preheat oven to 300°F. Place pans of turkey (still covered tightly with foil) in oven and heat for 30 to 45 minutes, or until heated through. Check turkey after ½ hour to avoid overheating. When turkey feels hot to the touch, lower oven temperature to 200°F. to keep warm until serving time. 8. Potatoes and stuffing can either be reheated in oven with the turkey or in the microwave. Reheat gravy in pot on stove until just boiling.