In a medium bowl, whisk together chopped cilantro, olive oil, fresh lemon juice, lemon zest, minced garlic, chicken bouillon, chili powder, chili flakes, cumin, salt, and black pepper. Divide the marinade into two equal portions for later use.

Place the chicken thighs in a ziplock bag or a large bowl, pour half of the marinade over them, ensuring they are well coated. Seal the bag or cover the bowl and refrigerate for at least 2 hours or overnight.

Preheat your grill pan over medium-high heat for about 5 minutes, adding 1 tablespoon of olive oil. If baking, preheat the oven to 400°F (200°C).

For grilling, cook the marinated chicken thighs for 4-5 minutes on each side until golden brown and the internal temperature reaches 165°F (75°C). For baking, cook uncovered for 18-20 minutes.

Remove the chicken thighs from the grill or oven, let them rest for a couple of minutes, then warm the reserved marinade and drizzle it over the chicken just before serving.