In a medium bowl, whisk together olive oil, lime juice, chili powder, cumin, garlic powder, salt, and pepper to make a marinade.

Place flank steak in a shallow dish, pour marinade over it, and massage into steak. Marinate for at least 30 minutes.

Take flank steak out of refrigerator 20 minutes before cooking to bring to room temperature. Preheat grill or skillet over medium-high heat.

Cook the flank steak for 4-5 minutes on each side for medium-rare. Only flip once to achieve a nice sear.

Let the steak rest for 5 minutes, then slice against the grain into thin strips.