In a zip-top bag, combine oil, salt, pepper, garlic and rosemary. Add steak and coat with oil and spices. Marinate in the fridge up to 24 hours.

Preheat grill to 350 degrees Fahrenheit. Grill three minutes per side, until internal temperature reaches 145 degrees Fahrenheit. (Alternatively, cook on the stove in a cast-iron pan for five minutes per side).

Let the steak rest at least 20 minutes before cutting.