1. Preheat your oven to 400 degrees Fahrenheit (200 degrees Celsius). Lightly grease a 9×13 inch baking dish.

2. In a large bowl, toss the cubed chicken with 1/2 teaspoon of the salt, 1/4 teaspoon of the black pepper, 1/2 teaspoon of the garlic powder, and 1/4 teaspoon of the onion powder. Heat the olive oil in a large skillet over medium-high heat. Add the seasoned chicken and cook for 3-4 minutes, just until lightly browned on the outside but still raw in the center. Remove chicken from skillet and set aside.

3. Add the potato chunks to the same skillet and cook for about 5-7 minutes, stirring occasionally, until slightly softened and lightly browned.

4. While potatoes cook, prepare the sauce: In a medium saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1 minute, stirring constantly, until a smooth paste forms. Gradually whisk in the milk, a little at a time, ensuring no lumps. Continue whisking until the sauce thickens to a creamy consistency, about 5-7 minutes. Remove from heat.

5. Stir in the remaining 1/4 teaspoon black pepper, 1/2 teaspoon garlic powder, 1/4 teaspoon onion powder, 1/2 teaspoon salt, and half of the mozzarella cheese and all of the Parmesan cheese into the sauce until melted and smooth.

6. Combine the partially cooked chicken and potatoes in the prepared baking dish. Pour the creamy cheese sauce evenly over the chicken and potatoes, making sure everything is well coated.

7. Sprinkle the remaining mozzarella cheese over the top.

8. Bake for 20-25 minutes, or until the potatoes are tender, the chicken is cooked through, and the cheese is bubbly and golden brown.

9. Remove from oven, let rest for 5 minutes, then garnish with fresh chopped parsley before serving.