Creating Stuffed Chicken Breast with Spinach and Cheese is straightforward if you follow these simple steps:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Prepare the Filling: In a mixing bowl, combine the chopped spinach, cream cheese, mozzarella, Parmesan, minced garlic, onion powder, Italian seasoning, salt, and pepper. Mix well until combined and creamy.
3. Prepare the Chicken: Take each chicken breast and slice it horizontally to create a pocket. Be careful not to cut all the way through.
4. Stuff the Chicken: Generously fill each chicken breast pocket with the spinach and cheese mixture, using toothpicks or kitchen twine to secure the opening if necessary.
5. Sear the Chicken: In a large oven-safe skillet, heat the olive oil over medium-high heat. Add the stuffed chicken breasts and sear for about 4-5 minutes on each side, until golden brown.
6. Bake: Transfer the skillet to the preheated oven and bake for 25-30 minutes or until the chicken is cooked through and no longer pink in the center.
7. Rest: Once done, remove the skillet from the oven and let the chicken rest for about 5 minutes before serving.
8. Serve: Carefully remove the toothpicks or twine from the chicken breasts before slicing and serving.

These easy steps will guide you in creating this delicious stuffed chicken dish effortlessly!