Peel and dice the potatoes, then place them in a large mixing bowl.
Add olive oil, garlic powder, smoked paprika, salt, and pepper to the potatoes and toss to combine.
Transfer the seasoned potatoes to an air fryer basket and cook at 400°F for 20 minutes, shaking halfway through. Set aside.
Toss the diced chicken breasts with Italian seasoning in a small bowl and set aside.
Melt butter in a large oven-safe skillet over medium-high heat.
Add the chicken to the skillet and cook, stirring frequently, until fully cooked.
Combine the cooked potatoes and garlic Parmesan sauce with the chicken in the skillet. Stir well and spread in an even layer.
Sprinkle the shredded mozzarella cheese evenly over the top.
Bake in a 400°F oven for 20-25 minutes until hot, bubbly, and golden brown on top.
Remove skillet from oven and let rest for 5 minutes before serving.