Season chicken with lemon pepper seasoning on both sides.
Dredge chicken in flour, shaking off excess.
Heat olive oil in a large skillet over medium-high heat.
Sear chicken in batches 4-5 minutes per side until golden and internal temp reaches 165F, then transfer to a plate.
Add 2 Tbsp butter to skillet and melt.
Add lemon slices and garlic, cook 30 seconds until fragrant.
Pour in chicken broth and scrape up browned bits from pan bottom.
Add lemon juice, lemon zest, and remaining 4 Tbsp butter, bring to a simmer.
Return chicken to skillet and baste with sauce for 1-2 minutes until warmed through.
Serve with pan sauce spooned over top and garnish with parsley if desired.