Season the chicken breasts with salt, pepper, and Italian seasoning. Heat olive oil and butter in a large skillet over medium heat. Add the chicken breasts and cook for 6-7 minutes per side until golden and cooked through. Remove from skillet and set aside. In the same skillet, add minced garlic and sauté until fragrant, about 1 minute. Pour in chicken broth to deglaze the pan, scraping any browned bits from the bottom. Stir in heavy cream and grated Parmesan cheese, simmering until the sauce thickens slightly. Add fresh spinach to the sauce and cook until wilted. Return chicken breasts to the skillet, spoon sauce over them, and cook for another 2-3 minutes to blend flavors. Serve hot, spooning the creamy spinach sauce over the chicken.