01 - Season both sides of each chicken breast with salt, pepper, and Italian seasoning, pressing gently to adhere.
02 - Heat olive oil and butter in a large skillet over medium-high heat. Add chicken and cook 5–7 minutes per side until golden brown and internal temperature reaches 165°F. Remove chicken and set aside on a plate.
03 - Reduce heat to medium. Add onion and garlic to the same skillet; sauté 2–3 minutes until fragrant and translucent, being careful not to burn the garlic.
04 - Pour in chicken broth, using a wooden spoon to scrape up browned bits from the bottom of the pan. Simmer for 2 minutes to reduce slightly.
05 - Stir in heavy cream and Parmesan cheese, whisking continuously until cheese melts and sauce is smooth. Simmer gently 2–3 minutes until slightly thickened.
06 - Return chicken to the skillet, turning to coat evenly in sauce. Simmer 3–5 minutes until heated through. Sprinkle with fresh parsley and additional Parmesan. Serve immediately.