In a food processor, combine the parsley, vinegar, oregano and crushed red pepper. Process until smooth; season with salt and pepper. Transfer the sauce to a bowl and pour the olive oil over the mixture. Let stand for at least 20 minutes.
Preheat oven to 450 degrees. Toss sweet potato batons in cornstarch and half of the taco taco seasoning. Then toss the coated batons in the chipotle olive oil. Spread in an even layer on a parchment lined baking sheet. Roast for 5-10 minutes until the edges start to brown. Take out of the oven and flip. Roast again for another 5-10 minutes until soft and lightly browned. Potatoes will crisp further as they cool.
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.