In a bowl, mix feta cheese with cream cheese, spinach, salt, pepper and the garlic and stir well.
Place chicken breasts on a working surface, cut a pocket in each, stuff them with the spinach and cheese mix and season them with salt and pepper to the taste.
Heat up a pan with the oil over medium-high heat, add stuffed chicken, cook for 5 minutes on each side to seal and then put in the oven at 375 degrees F.
Bake for 20 - 30 minutes, until the chicken is cooked fully and serve.
Enjoy!
** Nutrition per serving: 3 servings, Each has Calories 290, Fat 12g, Protein 24g, Carbs 4g