Prepare the Chicken : Preheat your oven to 375°F (190°C). Season the chicken breasts with garlic powder, onion powder, Italian seasoning, paprika, salt, and pepper.

Sear the Chicken : In a large oven-safe skillet, heat the olive oil over medium-high heat. Sear the chicken breasts for 3-4 minutes on each side until golden brown. Remove the chicken from the skillet and set aside.

Make the Sauce : In the same skillet, lower the heat to medium and add the minced garlic. Sauté for 1 minute until fragrant. Stir in the heavy cream, chicken broth, and Parmesan cheese. Cook for 2-3 minutes, stirring frequently, until the sauce starts to thicken slightly.

Assemble the Casserole : Add the fresh spinach leaves and chopped sun-dried tomatoes to the skillet, stirring until the spinach is wilted. Return the seared chicken breasts to the skillet, nestling them into the sauce. Sprinkle the shredded mozzarella cheese over the top.

Bake : Transfer the skillet to the preheated oven and bake for 25-30 minutes, or until the chicken is fully cooked and the cheese is melted and bubbly. The internal temperature of the chicken should reach 165°F (74°C).

Serve : Remove the casserole from the oven and let it rest for 5 minutes before serving. Garnish with additional Parmesan cheese or fresh herbs if desired. Serve hot with crusty bread, pasta, or a side salad.