01 - Pat chicken breasts dry and season generously with salt, pepper, and Italian seasoning on both sides, pressing the seasoning into the meat.
02 - Heat olive oil and butter in a large skillet over medium-high heat until shimmering. Add chicken breasts and cook for 5-7 minutes per side until golden brown and internal temperature reaches 165°F. Transfer chicken to a plate and tent with foil.
03 - Reduce heat to medium. Add chopped onion and minced garlic to the same skillet, sautéing for 2-3 minutes until fragrant, translucent, and lightly golden.
04 - Pour in chicken broth, using a wooden spoon to scrape up any browned bits from the bottom of the skillet. Let simmer for 2 minutes to reduce slightly.
05 - Stir in heavy cream and grated Parmesan cheese, whisking continuously until cheese melts and sauce is smooth and velvety. Simmer gently for 2-3 minutes until slightly thickened.
06 - Return chicken to the skillet, spooning sauce over the top to coat thoroughly. Simmer for 3-5 minutes until flavors meld and chicken is heated through.
07 - Sprinkle with fresh chopped parsley and additional Parmesan cheese if desired. Serve immediately alongside mashed potatoes, pasta, or steamed vegetables.