Preheat oven to 375°F (190°C).
Season chicken breasts inside and outside with salt, pepper, and paprika.
Heat olive oil in a skillet and sauté garlic and spinach 2–3 minutes until wilted.
Remove from heat and mix spinach with cream cheese, parmesan, mozzarella, and Italian seasoning.
Spoon filling into each chicken pocket and secure with toothpicks if needed.
Sear stuffed chicken 2–3 minutes per side in a skillet until lightly golden.
Transfer to oven and bake 18–22 minutes until internal temperature reaches 165°F (74°C).
Rest 5 minutes, garnish with parsley, and serve warm.