In a medium bowl, combine ¼ cup of olive oil with the juice of two limes, whisking until fully blended. Add 2 tablespoons of chili powder, 1 teaspoon of cumin, garlic powder, salt, and pepper to taste. Mix until a paste forms.

Place 1 pound of flank steak in a shallow dish or zip-top bag, pour the marinade over it, ensuring even coating. Massage into the meat. Allow marinating for at least 30 minutes.

Preheat your grill or cast-iron skillet over medium-high heat for at least 5 minutes.

Once hot, place the marinated flank steak on the surface, letting it sear for 4-5 minutes. Flip and cook the other side for another 4-5 minutes.

Remove from heat and let the steak rest for 5 minutes before slicing against the grain into thin strips.