Prepare the marinade by mixing lime juice, chili powder, garlic powder, cumin, salt, and pepper in a bowl.
Place the flank steak in a resealable plastic bag or dish, and pour the marinade over.
Preheat your grill or grill pan over medium-high heat.
Remove the steak from the marinade, shaking off any excess, and drizzle with olive oil.
Grill the flank steak for about 3-4 minutes on each side for medium-rare, adjusting time according to thickness.
Let the steak rest for 5-10 minutes before slicing to retain juices.
Slice the flank steak against the grain and serve with cilantro garnish.