Butter a 1-quart ceramic baking dish. Line the bottom of the dish with a layer of peas, and then a layer of stuffing, and then the turkey. Top with the mashed sweet potatoes (or mashed white potatoes.) Cover with aluminum foil and bake 30 minutes or until heated through. Uncover, and place under the broiler for about 3 to 5 minutes (watch carefully) until the top is crispy and golden, if desired.