In a bowl, combine olive oil, minced garlic, red wine vinegar, chopped parsley, oregano, salt, and black pepper. Pour this marinade over the hanger steak in a resealable bag. Seal the bag and refrigerate for at least 1 hour, preferably overnight.

Prepare the Potatoes

While the steak is marinating, wash and peel the russet potatoes. Cut them into thick fries. Soak the fries in water for at least 30 minutes to remove excess starch, then drain and pat dry.

Fry the Potatoes

In a large pot or deep fryer, heat vegetable oil to 350°F (175°C). Carefully add the fries in batches and fry until golden and crispy, about 5-7 minutes. Remove and drain on paper towels. Season with salt to taste.

Cook the Steak

Preheat a grill or skillet over high heat. Remove the steak from the marinade and let excess drip off. Grill or sear the steak for about 4-5 minutes per side for medium-rare, or until it reaches your desired doneness. Let it rest for 5 minutes before slicing.

Serve

Slice the steak against the grain and serve alongside the fries with chimichurri drizzled on top.