Ingredients :

• Ribeye (entrecôte) — The right choice here because its intramuscular fat melts during searing and keeps the cubes juicy. Avoid tenderloin: too lean, it dries out under intense heat. A striploin works if that’s what you have — slightly less melt-in-the-mouth but very decent.
• Flat-leaf parsley — Curly parsley has no place in this recipe. Flat-leaf parsley has more flavor, a suppler texture, and withstands chopping with a knife without turning into mush. Get it as fresh as possible — limp stems make for a dull sauce.
• Red wine vinegar — This is what gives chimichurri its characteristic bite. It tempers the heaviness of a pure oil sauce and cuts through the fat of the meat. Apple cider vinegar can substitute if needed — the result will be slightly sweeter and fruitier.
• Thai chili (Bird’s eye) — More direct and fresher than dried red pepper flakes. One or two are enough depending on your tolerance. If you can’t find any, a small fresh red chili works perfectly — remove the seeds to stay reasonable.