Creating Spinach Stuffed Chicken is simple when you follow these steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Prepare Filling: In a mixing bowl, combine the chopped spinach, ricotta cheese, Parmesan cheese, mozzarella cheese, minced garlic, Italian seasoning, salt, and pepper. Mix until well combined.
3. Prepare Chicken: Take the chicken breasts and make a pocket in each by slicing them horizontally, being careful not to cut all the way through.
4. Stuff Chicken: Fill each chicken breast pocket with the spinach and cheese mixture, ensuring it’s packed well.
5. Secure the Filling: Use toothpicks to secure the openings of each chicken breast, keeping the filling intact during cooking.
6. Heat Oil: In a large oven-safe skillet, heat olive oil over medium-high heat.
7. Sear Chicken: Add the stuffed chicken breasts to the skillet and sear for 3-4 minutes on each side until they are golden brown.
8. Bake: Transfer the skillet to the preheated oven and bake for 25-30 minutes, or until the chicken is cooked through and reaches an internal temperature of 165°F (75°C).
9. Rest: Remove the skillet from the oven and let the chicken rest for a few minutes before serving.
10. Garnish: Optionally, garnish with fresh basil before slicing and serving.

These steps will guide you in creating this incredible dish effortlessly. The combination of flavors and textures will leave everyone wanting more!