In a large bowl, combine the lemon juice, lemon zest, minced garlic, olive oil, dried oregano, salt, and black pepper to create the marinade.
Add the chicken breasts to the bowl, ensuring they are well coated in the marinade. Cover and refrigerate for at least 30 minutes (or up to 2 hours for more flavor).
Preheat your grill or skillet over medium-high heat. If using a skillet, add a drizzle of olive oil to prevent sticking.
Remove the chicken from the marinade and let the excess drip off. Grill or pan-sear the chicken for about 6-7 minutes per side, or until the internal temperature reaches 165°F (75°C) and the chicken is golden and cooked through.
Once cooked, transfer the chicken to a serving platter. Let it rest for a few minutes before slicing.
Garnish with freshly chopped parsley and lemon slices.
Notes
For best flavor, marinate the chicken for up to 2 hours.