In a medium bowl, combine chopped fresh cilantro, 4 tablespoons of olive oil, fresh lemon juice, lemon zest, minced garlic, chicken bouillon, chili powder, chili flakes, ground cumin, kosher salt, and black pepper. Whisk until well combined, creating a vibrant marinade. This flavor-packed blend is what makes the garlic lemon chicken thighs truly special. Divide the marinade into two portions for later use.

Place the boneless skinless chicken thighs in a resealable bag, then pour half of the prepared marinade over them. Seal the bag tightly, ensuring all the chicken is coated. Refrigerate for at least 2 hours, or overnight for the best flavor infusion. This essential step allows the garlic and lemon to penetrate the meat, resulting in tender, flavorful chicken thighs.

Shortly before you’re ready to cook, preheat a cast-iron grill pan over medium-high heat. Add the remaining 1 tablespoon of olive oil to the pan, allowing it to heat until shimmering. A properly heated pan ensures a beautiful sear on your garlic lemon chicken thighs, enhancing both flavor and texture.

Remove the chicken thighs from the marinade, letting any excess fall off. Place them in the hot grill pan and cook for 4–5 minutes on each side. Look for a golden-brown crust and ensure the internal temperature reaches 165°F for safe consumption. Juicy garlic lemon chicken thighs will yield a delicious aroma and a slight char that makes them irresistible.

Once cooked, drizzle the reserved marinade over the chicken thighs while they're still hot. Serve immediately, perhaps with a side of roasted vegetables, rice, or a fresh salad to balance the richness of the garlic lemon chicken thighs.