Whisk together the lemon juice, olive oil, minced garlic, salt, pepper, oregano, and thyme in a bowl.
Place the chicken breasts in a resealable bag or dish and pour the marinade over them. Marinate in the refrigerator for at least 30 minutes, or up to 2 hours.
Preheat the grill or a skillet over medium-high heat.
Remove the chicken from the marinade and discard the marinade.
Grill or cook the chicken for 6-7 minutes on each side, or until the internal temperature reaches 165°F (75°C).
Remove from heat, let rest for a few minutes, then garnish with lemon slices and fresh parsley before serving.
Notes
This recipe is forgiving; you can marinate for a bit longer without compromising texture. Use a meat thermometer for best results to avoid overcooking.