Preheat oven to 400°. In a medium bowl, whisk together flour, lemon pepper, salt, and zest of 1 lemon. Toss chicken breasts in the flour mixture until fully coated. Slice remaining lemon into thin rounds. In a large ovenproof skillet over medium-high heat, heat oil. Add chicken in a single layer and cook until golden on bottom, about 5 minutes, then flip chicken breasts. To skillet, add broth, butter, garlic, and lemon slices and bake until chicken is cooked through and sauce has reduced slightly, about 5 minutes. Spoon sauce on top of chicken and garnish with parsley. In a medium bowl, whisk together flour, lemon pepper, salt, and zest of 1 lemon. Toss chicken breasts in the flour mixture until fully coated. Slice remaining lemon into thin rounds. In a large ovenproof skillet over medium-high heat, heat oil. Add chicken in a single layer and cook until golden on bottom, about 5 minutes, then flip chicken breasts. To skillet, add broth, butter, garlic, and lemon slices and cook until chicken is cooked through and sauce has reduced slightly, 3 minutes. Spoon sauce on top of chicken and garnish with parsley.