01 - Season the chicken breasts with salt, pepper, and Italian seasoning on both sides, pressing gently to help the seasoning adhere.
02 - Heat olive oil and butter in a large skillet over medium-high heat. Add chicken breasts and cook for 5–7 minutes per side, until golden brown and cooked through. Remove the chicken and set aside on a plate.
03 - In the same skillet, reduce heat to medium. Add onion and garlic; sauté for 2–3 minutes until fragrant and translucent, being careful not to burn the garlic.
04 - Pour in the chicken broth, scraping up any browned bits from the bottom of the pan with a wooden spoon. Let it simmer for 2 minutes to reduce slightly.
05 - Stir in the heavy cream and Parmesan cheese, whisking constantly until the cheese is melted and the sauce is smooth. Simmer gently for another 2–3 minutes until slightly thickened.
06 - Return the chicken to the skillet, coating it in the sauce. Simmer for 3–5 minutes, allowing the flavors to meld together and the chicken to heat through.
07 - Sprinkle with fresh parsley and additional Parmesan, if desired. Serve immediately with mashed potatoes, pasta, or steamed green vegetables.