Rather than competing for space on the holiday table, Heinz has cooked up a tribute to the quieter star of the season: the day-after sandwich. With a wink to Friends lore, the company has released a novelty-leaning Leftover Gravy designed not for mashed potatoes, but for the beloved, overstuffed “Moist Maker” ritual that takes place in kitchens everywhere once the guests have gone home.