01 - Pat the chicken breasts dry with paper towels. Season both sides generously with salt and black pepper. Lightly dredge each breast in flour, coating evenly and shaking off excess powder.
02 - Heat olive oil and butter in a large skillet over medium-high heat until butter foams. Add chicken breasts and sear for 4–5 minutes per side until golden brown and internal temperature reaches 165°F. Transfer to a plate and tent loosely with foil.
03 - Reduce heat to medium. Add minced garlic to the same skillet and sauté for 1 minute until fragrant, being careful not to burn.
04 - Pour in chicken broth, using a wooden spoon to scrape up browned bits from the bottom of the skillet. Let simmer for 2 minutes to reduce slightly.
05 - Stir in heavy cream, lemon zest, and lemon juice. Bring to a gentle simmer, then gradually whisk in Parmesan cheese until fully melted. Continue cooking for 2–3 minutes until sauce thickens enough to coat the back of a spoon.
06 - Return chicken to the skillet, spooning sauce generously over each piece. Simmer for 3–4 minutes until heated through. Sprinkle with chopped parsley and red pepper flakes if using. Serve immediately, garnished with additional Parmesan and parsley.