01 - Pat chicken breasts dry with paper towels. Generously season both sides with salt, black pepper, and Italian seasoning, pressing the spices into the meat to ensure even coating.
02 - Heat olive oil and butter in a large skillet over medium-high heat until butter foams. 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 loosely with foil.
03 - Reduce heat to medium. Add chopped onion to the same skillet and sauté for 2 minutes until softened. Add minced garlic and cook for another minute until fragrant and translucent, being careful not to brown the garlic.
04 - Pour in chicken broth, using a wooden spoon to scrape up any browned bits from the bottom of the skillet. Let the mixture simmer for 2 minutes to reduce slightly and concentrate flavors.
05 - Pour in heavy cream and add grated Parmesan cheese. Whisk continuously until cheese melts and sauce is smooth and emulsified. Simmer gently for 2–3 minutes until sauce coats the back of a spoon and slightly thickens.
06 - Return chicken breasts to the skillet, turning to coat thoroughly in the sauce. Simmer for 3–5 minutes until chicken is heated through and flavors meld. Sprinkle with fresh parsley and additional Parmesan cheese before serving.