Season the chicken: Sprinkle both sides of the chicken breasts with salt, pepper, and Italian seasoning.
Sear the chicken: In a large skillet, heat the olive oil and butter over medium-high heat. Once the butter is melted and the pan is hot, add the chicken breasts. Sear for 4-5 minutes on each side, or until the chicken is golden brown and cooked through (internal temperature should be 165°F). Remove the chicken from the skillet and set it aside.
Sauté garlic: In the same skillet, add the minced garlic and cook for about 1 minute, until fragrant.
Deglaze the pan: Pour in the chicken broth, scraping up any browned bits from the bottom of the pan with a wooden spoon. Let the broth simmer for about 2 minutes.
Add cream and cheese: Stir in the heavy cream and Parmesan cheese. Continue to cook, stirring occasionally, until the sauce thickens and becomes creamy, about 3-5 minutes.
Wilt the spinach: Add the fresh spinach to the skillet and cook, stirring, until the spinach wilts and softens (about 2 minutes).
Combine the chicken and sauce: Return the chicken breasts to the skillet, spooning the sauce over the top. Simmer for an additional 5 minutes, allowing the flavors to meld.
Serve: Once the chicken is fully cooked and the sauce is creamy, remove from heat. Serve the chicken topped with the creamy spinach sauce.
