Combine olive oil, lime juice, cilantro, garlic, cumin, salt and pepper into a gallon size zip-lock bag. Then add the chicken thighs to the bag. Zip the bag shut and gently mix.
Let the chicken marinate for at least 30 minutes, but no longer than 3 hours.
When you are ready to cook, heat the grill to medium heat. Add the chicken thighs to the grill and cook for about 8 minutes per side. When the chicken reaches 165°F internally it is finished.
Remove from the grill, serve with desired toppings and enjoy.