Begin by preheating your oven to 375°F (190°C), ensuring it has ample time to reach the desired temperature.
In a medium skillet, pour in 1 tablespoon of olive oil and warm over medium heat. Once hot, add the minced garlic and sauté for approximately 30 seconds until it becomes fragrant, taking care not to burn it.
Next, add the chopped spinach to the skillet, stirring until it wilts, which should take about 2-3 minutes. Once wilted, remove the skillet from heat and allow it to cool slightly.
In a mixing bowl, combine the wilted spinach with the ricotta cheese, mozzarella cheese, Parmesan cheese, dried oregano, salt, and black pepper. Stir well to ensure all ingredients are evenly mixed and well incorporated.
With a sharp knife, carefully slice each chicken breast horizontally, creating a pocket. Make sure to slice deeply enough to allow for stuffing but avoid cutting all the way through.
Generously fill each chicken breast pocket with the spinach and cheese mixture, then secure the opening with toothpicks or by tying it with kitchen twine to prevent the filling from coming out during cooking.
In an oven-safe skillet, heat a couple of tablespoons of olive oil over medium-high heat. Once the oil is shimmering, gently place the stuffed chicken breasts in the skillet and sear them for 3-4 minutes on each side until they develop a gorgeous golden-brown crust.
Carefully transfer the skillet to the preheated oven and bake for 25-30 minutes. The chicken is done once its internal temperature reaches 165°F (75°C) and the juices run clear.
After baking, take the skillet out of the oven and allow the chicken to rest for about 5 minutes. This helps retain the juices for a succulent bite!
Once rested, delicately remove the toothpicks or twine. For a beautiful presentation, slice the chicken breasts in half (if desired) before serving.
Notes
For an exquisite finish, garnish with freshly chopped herbs like basil or parsley.