Chimichurri Sauce : In a bowl, combine parsley, garlic, oregano, and red pepper flakes. Stir in vinegar and olive oil. Season with salt and pepper. Set aside to let flavors meld.
Fries : Preheat oven to 425°F (220°C). Toss potatoes with olive oil and salt. Spread on a baking sheet and bake for 25–30 minutes, turning halfway, until crisp and golden.
Steak : Bring steak to room temperature and season generously with salt and pepper. Heat a skillet or grill over high heat with olive oil. Sear steak 3–5 minutes per side (depending on thickness and doneness). Rest steak for 5 minutes before slicing.