In a small bowl, whisk together the olive oil, lime juice, chili powder, garlic powder, onion powder, cumin, salt, and black pepper to create a marinade.
Place the flank steak in a large resealable plastic bag or shallow dish. Pour the marinade over the steak, ensuring it is well coated. Seal the bag or cover the dish and refrigerate for at least 1 hour, or up to 8 hours for more flavor.
Preheat your grill or grill pan over medium-high heat. Remove the steak from the marinade and discard the marinade.
Grill the flank steak for about 5-7 minutes on each side for medium-rare, or until it reaches your desired doneness.
Remove the steak from the grill and let it rest for 5 minutes before slicing against the grain.
Serve garnished with fresh cilantro and lime wedges on the side.