Spray a skillet with olive oil spray. Add the potatoes, onion, 1/4 teaspoon garlic powder, salt, and pepper. Cover the skillet and cook 11-13 minutes, stirring occasionally.
While the potatoes cook prepare the chicken. Cut it into 1/2" pieces then season with 1/4 teaspoon garlic powder, salt, and pepper.
When the potatoes are done cooking pour them into a bowl and cover with foil.
Add the chicken to the skillet and cook until no longer pink. Add the Parmesan garlic sauce and stir together. Pour the potatoes back in and stir together.
Top with the mozzarella cheese and cover with the lid until the cheese melts.