In a medium bowl, combine ¼ cup of fresh cilantro, 2 tablespoons of olive oil, 2 tablespoons of freshly squeezed lime juice, and 1 tablespoon of lime zest. Add 2 teaspoons of chili powder, 1 teaspoon of ground cumin, 1 teaspoon of kosher salt, and 1 teaspoon of freshly ground black pepper. Whisk the mixture well until fully blended, creating a vibrant marinade that will infuse the chicken thighs with zesty flavor.

Place the 2 pounds of boneless, skinless chicken thighs into a gallon-sized zip-top bag or a large mixing bowl. Pour the cilantro lime marinade over the chicken, ensuring each piece is evenly coated. Seal the bag or cover the bowl tightly, and refrigerate for at least 2 hours, or overnight for maximum flavor. Flip the chicken occasionally to marinate it evenly in the zesty concoction.

When you're ready to cook, remove the chicken thighs from the refrigerator. Drain them from the marinade, allowing excess liquid to drip off. Heat a cast iron grill pan over medium-high heat and add 1 tablespoon of olive oil. Ensure the oil shimmers before adding the chicken to create a beautiful sear.

Place the marinated chicken thighs in the hot grill pan without overcrowding. Cook each thigh for about 4-5 minutes on one side, or until they turn golden brown and easily release from the pan. Flip them over and continue cooking for another 4-5 minutes, making sure they are cooked through and reach an internal temperature of 165°F.

Once cooked, transfer the cilantro lime chicken thighs to a plate and allow them to rest for 5 minutes. This step helps retain the juices for the ultimate tenderness. For an added touch, garnish with fresh cilantro before serving. Enjoy these flavorful thighs in tacos, burrito bowls, or simply alongside your favorite sides!