In a bowl, combine the chopped cilantro, minced garlic, olive oil, salt, black pepper, and lime juice to create a marinade. Place the hanger steak in a resealable plastic bag or a shallow dish and pour the marinade over the steak. Ensure it’s well coated. Marinate in the refrigerator for at least 1 hour, or up to overnight for more flavor.

Rinse the julienned potatoes in cold water to remove excess starch. Pat them dry with paper towels. Heat the vegetable oil in a deep fryer or large heavy pot over medium-high heat. Fry the potatoes in batches until golden brown and crispy, about 4-5 minutes per batch. Use a slotted spoon to transfer the fries to a paper towel-lined plate. Sprinkle with sea salt while hot.

Preheat a grill or skillet over medium-high heat. Remove the steak from the marinade, allowing excess to drip off. Grill the steak for about 4-5 minutes on each side for medium-rare, or longer to reach your desired doneness. Let the steak rest for 5 minutes before slicing against the grain.

In a small bowl, mix together the Greek yogurt, mayonnaise, parsley, dill, lemon juice, salt, and pepper until well combined. Adjust seasoning to taste.

Slice the hanger steak and serve it alongside the sea-salted matchstick fries. Drizzle the zesty herb sauce over the steak or serve it on the side for dipping.