01 - Whisk olive oil, lemon juice, lemon zest, garlic, Dijon mustard, honey, oregano, salt, and pepper in a bowl until combined.
02 - Place chicken breasts in a shallow dish and pour half the marinade over them, turning to ensure even coating. Reserve remaining marinade and marinate chicken for at least 10 minutes or up to 1 hour for enhanced flavor.
03 - Melt 1 tablespoon butter in a large skillet over medium-high heat. Remove chicken from marinade and discard used marinade. Sear chicken for 5 to 6 minutes per side until golden brown and fully cooked (internal temperature 165°F). Transfer to a plate and loosely cover with foil.
04 - Add reserved marinade and chicken broth to the skillet. Bring to a simmer, scraping any browned bits from the pan. Let the sauce reduce for 3 to 4 minutes until slightly thickened.
05 - Whisk in remaining butter to enrich the sauce. Return chicken to the skillet, spoon sauce over each breast, and simmer together for 1 minute to warm through.
06 - Plate chicken with sauce spooned on top. Garnish with chopped parsley and lemon slices before serving.