In a medium mixing bowl, combine the chopped spinach, ricotta cheese, Parmesan cheese, cream cheese, minced garlic, Italian seasoning, salt, and black pepper. Mix well until all ingredients are combined into a creamy filling.
Carefully slice a pocket into each chicken breast, making sure not to cut all the way through.
Stuff each chicken breast with an equal amount of the creamy spinach filling. Use toothpicks to secure the openings if necessary.
Heat the olive oil in a large oven-safe skillet over medium heat. Once hot, add the stuffed chicken breasts and sear for 3-4 minutes on each side, until golden brown.
Transfer the skillet to the preheated oven and bake for 20-25 minutes, or until the chicken is cooked through (internal temperature should reach 165°F/74°C).
Once cooked, remove from the oven and let the chicken rest for 5 minutes before serving.
Serve the stuffed chicken garnished with halved cherry tomatoes and fresh basil leaves.
Notes
Let the chicken rest before serving for better flavor.