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 until golden brown and cooked through, about 6-7 minutes per side. Remove chicken and set aside.
In the same skillet, add minced garlic and sauté for 1 minute until fragrant.
Pour in chicken broth and bring to a simmer, scraping up any browned bits from the pan.
Stir in heavy cream and grated Parmesan cheese, cooking until the sauce thickens slightly.
Add fresh spinach and cook until wilted.
Return the chicken breasts to the skillet, spoon the sauce over them, and simmer for an additional 3-4 minutes.
Serve hot, garnished with extra Parmesan if desired.