Preheat grill to medium-high heat.
Pat dry steak & rub olive oil to coat evenly. On a plate, add ½ of taco seasoning packet and coat flank steak evenly. Flip steak over and add more seasoning to plate if necessary. Cover steak completely in the rub.
Lightly grease grill and lay flank steak on it for about 4-5 minutes. Turn and cook 3-4 minutes more for medium rare. If going for medium or beyond, place on the second tier of grill and cover for 5 more minutes.
To get a juicy piece of steak, let it rest on cutting board, covered with aluminum foil, for about 5-7 minutes. Slice against the grain and serve with salsa verde or pico de gallo.