Pat steak dry, season with salt, pepper, garlic powder, drizzle oil, rest 15 min.
Mix parsley, cilantro, garlic, olive oil, vinegar, lime, spices for chimichurri.
Preheat grill to high, cook steak 4–5 min per side, flip once.
Rest 5 min under foil, slice against grain, top with chimichurri, serve.