Spatchcock the chicken by removing the backbone and flattening it.
Spread 2 tablespoons of mustard over the entire chicken as a binder.
Season the chicken liberally with your favorite chicken rub on both sides.
Poke holes in 3-4 large russet potatoes.
Coat the potatoes lightly with olive oil and season with salt.
Wrap each potato in aluminum foil.
Preheat the smoker to 250 degrees Fahrenheit using apple wood chunks.
Place the foil-wrapped potatoes on the smoker.
After 45 minutes of smoking the potatoes, add the chicken breast side up to the smoker.
Smoke the chicken until it reaches an internal temperature of 160°F.
Continue cooking the potatoes until they are tender when poked with a fork.
Rest the chicken for 20 minutes after smoking.