01 - Place each chicken breast between two sheets of plastic wrap and pound to 1/2-inch thickness. Season both sides with salt and pepper.
02 - Dredge the chicken breasts lightly in flour, shaking off excess.
03 - Heat olive oil and 2 tablespoons of butter in a large skillet over medium-high heat. Add chicken and cook for 3–4 minutes per side, until golden and cooked through. Remove to a plate and tent with foil.
04 - Pour wine (or broth) into the pan, scraping up browned bits. Let simmer for 2 minutes.
05 - Add lemon juice and capers. Simmer 2 minutes more.
06 - Return chicken to the skillet, spoon sauce over, and simmer 2–3 minutes. Remove from heat. Stir in remaining 2 tablespoons butter and sprinkle with chopped parsley.
07 - Serve immediately, spooning sauce over the chicken.