In a large bowl, combine olive oil, lemon juice, minced garlic, oregano, thyme, salt, and black pepper. Whisk until well blended.
Add the chicken thighs to the marinade, ensuring they are well coated. Cover and refrigerate for at least 30 minutes, or up to 2 hours for more flavor.
Preheat your grill or a large skillet over medium-high heat.
Remove the chicken from the marinade, allowing excess marinade to drip off. Discard the remaining marinade.
Grill or cook the chicken for about 6-7 minutes on each side, or until the internal temperature reaches 165°F and the chicken is golden brown.
Remove the chicken from the heat and let it rest for 5 minutes.
Serve garnished with lemon slices and chopped parsley.