Crack the egg into a small bowl and whisk it up.
Add your stuffing to a bowl and pour the whisked egg in. Stir until the egg is well combined in the stuffing.
Warm up a waffle iron and spray with cooking spray. Scoop about 1 cup of the stuffing onto the iron and cook until it is crispy.
Warm the mashed potatoes and gravy in the microwave. Top each waffle with a large scoop of mashed potatoes (about 1/2 cup) and drizzle with gravy. Enjoy!