In the meantime, heat a grill pan over high heat until very hot. Slice the flank steak against the grain into 24 strips, about 1/8 inch thick. Season with salt & pepper and the other half of the taco taco seasoning. Lightly coat the pan with a bit of chipotle olive oil. Flash grill strips of steak, about 1 minute per side and remove from the grill. Wrap steak strips around three of the potato batons and poke through with a skewer. Top with chimichurri sauce.